Pathway Human Homo sapiens

HCMV Infection

R-HSA-9609646 in Reactome release 97: under Viral Infection Pathways, with 293 genes placed in it by the mapping files and 2 child pathways in the hierarchy.

The same number in the other species

Reactome writes the mouse and rat events it infers from a human pathway under the human number with the species token. A door opens only where that species' own list in this release holds the id; neither of the other two lists holds it. Whether the event was inferred from this one is what the record says.

The record
The genes
Parents and children

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This page reads the pathway's record from its source while you read the rest; with scripts off the card stays at its loading line. Reload with scripts on to see it, or open the source's own page from the link in the card.

01The record

Reactome's own record of this pathway

What this tells you

The pathway list, the hierarchy and the genes on this page are read from the files Reactome publishes for Reactome release 97, built into this site on 2026-09-09: the pathway list, the hierarchy relationship file and the two gene mapping files. The record card is the one live read, Reactome's own record of this pathway.

Reactome's download page describes the mapping files: Mapping files link the source database identifier to the lowest level pathway diagram or subset of the pathway, all levels of the pathway hierarchy or database identifier to all reactions. [R13] The gene list here is the all-levels mapping of NCBI Gene ids, filled from the all-levels mapping of Ensembl ids where the NCBI file has no row for a gene; each row names which file it came from by the shape of its source id. Each row carries the evidence codes the file writes for it, as written and unranked, and both where the file writes both; no page of Reactome's documentation the survey read defines the codes, so this page does not expand them. A gene id the identity files do not name is kept as the source's own id with no door rather than turned into a symbol.

On citing what a search finds, Reactome says: It should be remembered that while we strive to contain the most current and accurate data, Reactome should not be used in citations where other primary sources of information are available. [R12] The record card prints the literature Reactome attaches to a curated pathway for that reason. The data are public domain: All data in the Reactome database and files derived from that data are licensed under the Creative Commons Public Domain Dedication (CC0). User may copy, modify, and distribute these data, even for commercial purposes, without asking for permission. Attribution is encouraged but not required. [R10] The pathway illustrations are licensed apart, under CC BY 4.0, and none is shown here.

A gene on this list is one Reactome places in this pathway in this release, and that is all the row says: it does not say the gene is expressed in a tissue or associated with a disease, which are the other two explorers' questions, read from other sources. Reactome's papers of record are [R01] [R02].

[R01] Ragueneau E, Gong C, Sinquin P, Sevilla C, Beavers D, Grentner A, et al. (2026). The Reactome Knowledgebase 2026. Nucleic Acids Research 54:D673-D681. PMID 41251150, doi 10.1093/nar/gkaf1223.
[R02] Milacic M, Beavers D, Conley P, Gong C, Gillespie M, Griss J, et al. (2024). The Reactome Pathway Knowledgebase 2024. Nucleic Acids Research 52:D672-D678. PMID 37941124, doi 10.1093/nar/gkad1025.
[R10] Reactome, reactome.org. License Agreement. https://reactome.org/license, read 2026-09-09.
[R12] Reactome, reactome.org. Citing us. https://reactome.org/cite, read 2026-09-09.
[R13] Reactome, reactome.org. Download. https://reactome.org/download-data, read 2026-09-09.

Stable id: R-HSA-9609646.5
Class: Pathway
Species: Homo sapiens (human)
Inferred: no: a curated human pathway
Disease pathway: yes, as Reactome flags it
Released: 2019-12-10
Last updated: 2021-09-15
Events inside: 2, counted from the record

Herpesviruses have a unique four-layered structure: a core containing the large, double-stranded DNA genome is enclosed by an icosapentahedral capsid which is composed of capsomers. The capsid is surrounded by an amorphous protein coat called the tegument. It is encased in a glycoprotein-bearing lipid bilayer envelope.

Herpesviruses are divided into three groups: alpha-herpesviruses, beta-herpesviruses, and gamma-herpesviruses. The beta herpesviruses have a restricted host range. Their reproductive life cycle is long (days), with infection progressing slowly in cell culture systems. These viruses cause their host cells to enlarge, as exemplified by a human cytomegalovirus (HCMV) infection. These viruses can establish latent infection in secretory glands, cells of the reticuloendothelial system, and the kidneys.

Human Cytomegalovirus, or HCMV, is a common virus that infects people of all ages. In the United States, nearly one in three children are already infected with HCMV by age 5 years. Over half of adults by age 40 have been infected with HCMV. Once HCMV is in a person’s body, it stays there for life and can reactivate.

Cytomegalovirus causes three clinical syndromes:

(1) Congenital cytomegalovirus infection (when symptomatic) causes hepatosplenomegaly, retinitis, rash, and central nervous system involvement.

(2) In about 10 per cent of older children and adults, primary cytomegalovirus infection causes a mononucleosis syndrome with fever, malaise, atypical lymphocytosis, and pharyngitis.

(3) Immunocompromised hosts (transplant recipients and human immunodeficiency virus [HIV]-infected individuals) may develop life-threatening disseminated disease involving the lungs, gastrointestinal tract, liver, retina, and central nervous system.

Experimentally HCMV can be propagated in multiple cell lines. When propagated in human fibroblasts, HCMV clinical isolates acquire mutations in a manner that suggests a process of adaptation. Two strains of HCMV AD169 (grown from cultures of adenoid tissue taken from a 7-year-old girl) and Towne (developed as an attenuated vaccine by passaging 125 times in vitro) were initially used as the primary clinical strains. As only 26 % of HCMV canonical genes (45/171) are essential for viral replication in vitro it became important that a model strain be developed.

The Merlin BAC was derived for this use. Produced using a bacterial artificial chromosome (BAC) cloning system (to avoid adaptation/degradation of the genome with each passage) the Merlin strain contains a complete HCMV genome that is thought to accurately to represent the original clinical agent from which it was derived. It is also a reproducible source of clonal virus (via transfection) and is capable of reconstituting phenotypically wild-type virus.

The lifecycle represented here uses the Merlin strain where possible.Infectious Human Cytomegalovirus (HCMV) particles enter the cell through interaction with cellular receptors. Once in the cytoplasm capsid and tegument proteins are delivered to the cytosol. The capsid travels to the nucleus, where the genome is delivered and circularized. Tegument proteins regulate host cell responses and initiate the expression of viral I immediate early genes. This is followed by delayed early genes, which initiate viral genome replication, then late genes. Late gene expression initiates capsid assembly in the nucleus, followed by nuclear egress to the cytosol. Capsids associate with tegument proteins in the cytosol and are trafficked to the viral assembly complex that contains components from the endoplasmic reticulum, Golgi apparatus, and endosomal machinery. The capsids acquire additional tegument proteins and a viral envelope by budding into intracellular vesicles. These vesicles fuse with the plasma membrane to release enveloped infectious particles along with non-infectious dense bodies.

Literature Reactome attaches

Human Cytomegalovirus (HCMV) - RevisedTransfus Med Hemother, 2010, vol. 37, p. 365-375PubMed 21483467
Human cytomegalovirus: taking the strainMed. Microbiol. Immunol., 2015, vol. 204, p. 273-84PubMed 25894764
Fields Virology2013
The life cycle and pathogenesis of human cytomegalovirus infection: lessons from proteomicsExpert Rev Proteomics, 2014, vol. 11, p. 697-711PubMed 25327590

Reactome ContentService, this pathway's record · Reactome v97 · read 2026-10-05 ET · Reactome pathway browser"HCMV Infection". Reactome, release 97, https://reactome.org/PathwayBrowser/#/R-HSA-9609646 with StableID: R-HSA-9609646.5 (accessed 2026-10-05 ET). Reactome version 97 (CC0).

Reading this pathway's record from Reactome (the pathway record).Still reading. A first read of a pathway can take a while; this page waits up to 35 seconds for it, and its scripts then bring in the panel, or a line saying what did not arrive.

02The genes

Genes Reactome places in this human pathway

The mapping files place 293 genes in this human pathway; showing 201 to 293, in pages of 100, sorted by symbol for reading. The order carries no ranking. 93 of the rows shown carry an id the identity file does not name, kept as the source wrote it.

Genes Reactome places in this human pathway, page 3 of 3
Gene	Authority id	Mapping file id	Evidence codes
Geneno symbol in the identity file	Authoritynone	Mapping file id3077460 NCBI file	EvidenceTAS
Geneno symbol in the identity file	Authoritynone	Mapping file id3077462 NCBI file	EvidenceTAS
Geneno symbol in the identity file	Authoritynone	Mapping file id3077463 NCBI file	EvidenceTAS
Geneno symbol in the identity file	Authoritynone	Mapping file id3077464 NCBI file	EvidenceTAS
Geneno symbol in the identity file	Authoritynone	Mapping file id3077465 NCBI file	EvidenceTAS
Geneno symbol in the identity file	Authoritynone	Mapping file id3077466 NCBI file	EvidenceTAS
Geneno symbol in the identity file	Authoritynone	Mapping file id3077471 NCBI file	EvidenceTAS
Geneno symbol in the identity file	Authoritynone	Mapping file id3077472 NCBI file	EvidenceTAS
Geneno symbol in the identity file	Authoritynone	Mapping file id3077473 NCBI file	EvidenceTAS
Geneno symbol in the identity file	Authoritynone	Mapping file id3077474 NCBI file	EvidenceTAS
Geneno symbol in the identity file	Authoritynone	Mapping file id3077475 NCBI file	EvidenceTAS
Geneno symbol in the identity file	Authoritynone	Mapping file id3077479 NCBI file	EvidenceTAS
Geneno symbol in the identity file	Authoritynone	Mapping file id3077480 NCBI file	EvidenceTAS
Geneno symbol in the identity file	Authoritynone	Mapping file id3077481 NCBI file	EvidenceTAS
Geneno symbol in the identity file	Authoritynone	Mapping file id3077482 NCBI file	EvidenceTAS
Geneno symbol in the identity file	Authoritynone	Mapping file id3077484 NCBI file	EvidenceTAS
Geneno symbol in the identity file	Authoritynone	Mapping file id3077485 NCBI file	EvidenceTAS
Geneno symbol in the identity file	Authoritynone	Mapping file id3077486 NCBI file	EvidenceTAS
Geneno symbol in the identity file	Authoritynone	Mapping file id3077487 NCBI file	EvidenceTAS
Geneno symbol in the identity file	Authoritynone	Mapping file id3077489 NCBI file	EvidenceTAS
Geneno symbol in the identity file	Authoritynone	Mapping file id3077490 NCBI file	EvidenceTAS
Geneno symbol in the identity file	Authoritynone	Mapping file id3077493 NCBI file	EvidenceTAS
Geneno symbol in the identity file	Authoritynone	Mapping file id3077494 NCBI file	EvidenceTAS
Geneno symbol in the identity file	Authoritynone	Mapping file id3077495 NCBI file	EvidenceTAS
Geneno symbol in the identity file	Authoritynone	Mapping file id3077496 NCBI file	EvidenceTAS
Geneno symbol in the identity file	Authoritynone	Mapping file id3077497 NCBI file	EvidenceTAS
Geneno symbol in the identity file	Authoritynone	Mapping file id3077498 NCBI file	EvidenceTAS
Geneno symbol in the identity file	Authoritynone	Mapping file id3077500 NCBI file	EvidenceTAS
Geneno symbol in the identity file	Authoritynone	Mapping file id3077501 NCBI file	EvidenceTAS
Geneno symbol in the identity file	Authoritynone	Mapping file id3077502 NCBI file	EvidenceTAS
Geneno symbol in the identity file	Authoritynone	Mapping file id3077503 NCBI file	EvidenceTAS
Geneno symbol in the identity file	Authoritynone	Mapping file id3077504 NCBI file	EvidenceTAS
Geneno symbol in the identity file	Authoritynone	Mapping file id3077506 NCBI file	EvidenceTAS
Geneno symbol in the identity file	Authoritynone	Mapping file id3077508 NCBI file	EvidenceTAS
Geneno symbol in the identity file	Authoritynone	Mapping file id3077509 NCBI file	EvidenceTAS
Geneno symbol in the identity file	Authoritynone	Mapping file id3077511 NCBI file	EvidenceTAS
Geneno symbol in the identity file	Authoritynone	Mapping file id3077512 NCBI file	EvidenceTAS
Geneno symbol in the identity file	Authoritynone	Mapping file id3077513 NCBI file	EvidenceTAS
Geneno symbol in the identity file	Authoritynone	Mapping file id3077514 NCBI file	EvidenceTAS
Geneno symbol in the identity file	Authoritynone	Mapping file id3077515 NCBI file	EvidenceTAS
Geneno symbol in the identity file	Authoritynone	Mapping file id3077516 NCBI file	EvidenceTAS
Geneno symbol in the identity file	Authoritynone	Mapping file id3077517 NCBI file	EvidenceTAS
Geneno symbol in the identity file	Authoritynone	Mapping file id3077518 NCBI file	EvidenceTAS
Geneno symbol in the identity file	Authoritynone	Mapping file id3077519 NCBI file	EvidenceTAS
Geneno symbol in the identity file	Authoritynone	Mapping file id3077520 NCBI file	EvidenceTAS
Geneno symbol in the identity file	Authoritynone	Mapping file id3077521 NCBI file	EvidenceTAS
Geneno symbol in the identity file	Authoritynone	Mapping file id3077522 NCBI file	EvidenceTAS
Geneno symbol in the identity file	Authoritynone	Mapping file id3077523 NCBI file	EvidenceTAS
Geneno symbol in the identity file	Authoritynone	Mapping file id3077524 NCBI file	EvidenceTAS
Geneno symbol in the identity file	Authoritynone	Mapping file id3077525 NCBI file	EvidenceTAS
Geneno symbol in the identity file	Authoritynone	Mapping file id3077526 NCBI file	EvidenceTAS
Geneno symbol in the identity file	Authoritynone	Mapping file id3077527 NCBI file	EvidenceTAS
Geneno symbol in the identity file	Authoritynone	Mapping file id3077528 NCBI file	EvidenceTAS
Geneno symbol in the identity file	Authoritynone	Mapping file id3077529 NCBI file	EvidenceTAS
Geneno symbol in the identity file	Authoritynone	Mapping file id3077530 NCBI file	EvidenceTAS
Geneno symbol in the identity file	Authoritynone	Mapping file id3077531 NCBI file	EvidenceTAS
Geneno symbol in the identity file	Authoritynone	Mapping file id3077532 NCBI file	EvidenceTAS
Geneno symbol in the identity file	Authoritynone	Mapping file id3077533 NCBI file	EvidenceTAS
Geneno symbol in the identity file	Authoritynone	Mapping file id3077534 NCBI file	EvidenceTAS
Geneno symbol in the identity file	Authoritynone	Mapping file id3077536 NCBI file	EvidenceTAS
Geneno symbol in the identity file	Authoritynone	Mapping file id3077537 NCBI file	EvidenceTAS
Geneno symbol in the identity file	Authoritynone	Mapping file id3077538 NCBI file	EvidenceTAS
Geneno symbol in the identity file	Authoritynone	Mapping file id3077539 NCBI file	EvidenceTAS
Geneno symbol in the identity file	Authoritynone	Mapping file id3077541 NCBI file	EvidenceTAS
Geneno symbol in the identity file	Authoritynone	Mapping file id3077542 NCBI file	EvidenceTAS
Geneno symbol in the identity file	Authoritynone	Mapping file id3077543 NCBI file	EvidenceTAS
Geneno symbol in the identity file	Authoritynone	Mapping file id3077545 NCBI file	EvidenceTAS
Geneno symbol in the identity file	Authoritynone	Mapping file id3077546 NCBI file	EvidenceTAS
Geneno symbol in the identity file	Authoritynone	Mapping file id3077547 NCBI file	EvidenceTAS
Geneno symbol in the identity file	Authoritynone	Mapping file id3077548 NCBI file	EvidenceTAS
Geneno symbol in the identity file	Authoritynone	Mapping file id3077549 NCBI file	EvidenceTAS
Geneno symbol in the identity file	Authoritynone	Mapping file id3077551 NCBI file	EvidenceTAS
Geneno symbol in the identity file	Authoritynone	Mapping file id3077553 NCBI file	EvidenceTAS
Geneno symbol in the identity file	Authoritynone	Mapping file id3077554 NCBI file	EvidenceTAS
Geneno symbol in the identity file	Authoritynone	Mapping file id3077557 NCBI file	EvidenceTAS
Geneno symbol in the identity file	Authoritynone	Mapping file id3077558 NCBI file	EvidenceTAS
Geneno symbol in the identity file	Authoritynone	Mapping file id3077559 NCBI file	EvidenceTAS
Geneno symbol in the identity file	Authoritynone	Mapping file id3077560 NCBI file	EvidenceTAS
Geneno symbol in the identity file	Authoritynone	Mapping file id3077561 NCBI file	EvidenceTAS
Geneno symbol in the identity file	Authoritynone	Mapping file id3077562 NCBI file	EvidenceTAS
Geneno symbol in the identity file	Authoritynone	Mapping file id3077563 NCBI file	EvidenceTAS
Geneno symbol in the identity file	Authoritynone	Mapping file id3077564 NCBI file	EvidenceTAS
Geneno symbol in the identity file	Authoritynone	Mapping file id3077566 NCBI file	EvidenceTAS
Geneno symbol in the identity file	Authoritynone	Mapping file id3077567 NCBI file	EvidenceTAS
Geneno symbol in the identity file	Authoritynone	Mapping file id3077569 NCBI file	EvidenceTAS
Geneno symbol in the identity file	Authoritynone	Mapping file id3077571 NCBI file	EvidenceTAS
Geneno symbol in the identity file	Authoritynone	Mapping file id3077572 NCBI file	EvidenceTAS
Geneno symbol in the identity file	Authoritynone	Mapping file id3077574 NCBI file	EvidenceTAS
Geneno symbol in the identity file	Authoritynone	Mapping file id3077575 NCBI file	EvidenceTAS
Geneno symbol in the identity file	Authoritynone	Mapping file id3077576 NCBI file	EvidenceTAS
Geneno symbol in the identity file	Authoritynone	Mapping file id3077577 NCBI file	EvidenceTAS
Geneno symbol in the identity file	Authoritynone	Mapping file id3077578 NCBI file	EvidenceTAS
Geneno symbol in the identity file	Authoritynone	Mapping file id3077579 NCBI file	EvidenceTAS

Evidence codes on this page: TAS, as the mapping file writes them; a row carrying two was written twice by the file, once under each. The mapping file id says which file placed the gene: an NCBI Gene id from NCBI2Reactome_All_Levels.txt, an Ensembl gene id from Ensembl2Reactome_All_Levels.txt. The two files can disagree about a code, so a row's codes are the one file's view. Measured by this site's build over this release on 2026-09-09: of the 138,908 human pathway-gene pairs both files place, 207 (0.149 per cent, over 47 genes) carry TAS in the Ensembl file where the NCBI rows carry IEA alone.

Reactome mapping files, the human rows for this pathway · Reactome release 97 · read 2026-09-09 · Reactome downloads"NCBI2Reactome_All_Levels.txt" and "Ensembl2Reactome_All_Levels.txt", Reactome, release 97, https://reactome.org/download-data/ (date of access 2026-09-09). Data CC0; attribution encouraged.

03The hierarchy

Parents and children in this release's hierarchy

Parents

Viral Infection PathwaysR-HSA-98244461,279 genes

Children

Reactome's hierarchy is a graph rather than a tree: a pathway can sit under more than one parent, and the gene counts are each pathway's own placements at every level under it, so a parent's count is not the sum of its children's.

Reactome, the human pathway list and hierarchy relationship file · Reactome release 97 · read 2026-09-09 · Reactome downloads"ReactomePathways.txt" and "ReactomePathwaysRelation.txt", Reactome, release 97, https://reactome.org/download-data/ (date of access 2026-09-09). Data CC0; attribution encouraged.