The article discusses the integration of viruses and cellular organisms into the KEGG (Kyoto Encyclopedia of Genes and Genomes) database, a comprehensive resource that integrates eighteen databases categorized into systems, genomic, chemical, and health information. KEGG provides mapping tools to understand cellular and organism-level functions from genome sequences and molecular datasets. The introduction of the KEGG NETWORK database has allowed for the association of various diseases with network variants, which are perturbed molecular networks caused by human gene variants, viruses, pathogens, and environmental factors. The network variation maps show how different viruses can inhibit or activate specific cellular signaling pathways. The KEGG pathway maps are now integrated with network variation maps in the NETWORK database and conserved functional units in the MODULE database. The KO database for functional orthologs continues to be improved, with virus KOs being expanded to better understand virus-cell interactions and predict viral perturbations. The article also highlights new developments in KEGG, including the release of a new pathway map viewer and the integration of drug information. The KEGG database is self-sustaining, relying on community funding for development and maintenance, and is updated daily.The article discusses the integration of viruses and cellular organisms into the KEGG (Kyoto Encyclopedia of Genes and Genomes) database, a comprehensive resource that integrates eighteen databases categorized into systems, genomic, chemical, and health information. KEGG provides mapping tools to understand cellular and organism-level functions from genome sequences and molecular datasets. The introduction of the KEGG NETWORK database has allowed for the association of various diseases with network variants, which are perturbed molecular networks caused by human gene variants, viruses, pathogens, and environmental factors. The network variation maps show how different viruses can inhibit or activate specific cellular signaling pathways. The KEGG pathway maps are now integrated with network variation maps in the NETWORK database and conserved functional units in the MODULE database. The KO database for functional orthologs continues to be improved, with virus KOs being expanded to better understand virus-cell interactions and predict viral perturbations. The article also highlights new developments in KEGG, including the release of a new pathway map viewer and the integration of drug information. The KEGG database is self-sustaining, relying on community funding for development and maintenance, and is updated daily.