MSigDB v2026.1.Mm (Jan 2026)

Important Notices#

• This page describes updates made to the Molecular Signatures Database Mouse Collections for release 2026.1 (MSigDB 2026.1.Mm).

• MSigDB v2026.1 is based on gene annotation data from Ensembl Release 115 (September 2026).

• In order to access the MSigBD mouse collections through the GSEA UI, the GSEA 4.3.0 or newer is required.

Updates to Mouse Collections (MSigDB v2026.1.Mm)#

M1: Positional gene sets#

As previously noted in the MSigDB v2022.1.Mm Release Notes the underlying data for the M1 collection remains based on the cytogenetic band annotations provided in the Ensembl 102 release, corresponding to the GRCm38 assembly as cytogentic band annotations for GRCm39 remain unavailable, however gene identifiers have been updated to Ensembl 115.

M2:CGP#

Gene sets from 3 publications have been added to C2:CGP, these gene sets consist of:

• A consensus signature of senescent cancer assoicated fibroblasts Ye et al. and Belle et al.
• A P53-dependent tumor suppression associated mechanism signature from Bieging-Rolett et al.
• Sets describing the transcriptional response to reactivation of P53 in lung adenocarcinoma cell lines from Wang et al.

M2:CP:Reactome#

• Reactome gene sets have been updated to reflect the state of the Reactome pathway architecture as of Reactome v95 (+24 gene sets).
• As previously described in the Reactome release notes for MSigDB 7.0, in order to limit redundancy between gene sets within the Reactome sub-collection we applied a filtering procedure based on Jaccard coefficients and distance from the top level of the Reactome event hierarchy.

M2:CP:WikiPathways#

WikiPathways gene sets have been updated to the January 10, 2026 release (+10 gene sets).

M5:GO (Gene Ontology)#

Gene sets in these sub-collections are derived from the controlled vocabulary of the Gene Ontology (GO) project: The Gene Ontology Consortium. Gene Ontology: tool for the unification of biology (Nature Genet 2000). The gene sets are named by GO term and contain genes annotated by that term. This collection has been updated to the most recent GO annotations at the time of release production using annotations in the GO-basic obo file released on 2025-10-10 and NCBI gene2go annotations downloaded on 2025-12-14.

This collection is divided into three sub-collections:

• BP: GO Biological process (-74 gene sets). Gene sets derived from the Biological Process Ontology; set names are prefixed with GOBP_.
• CC: GO Cellular component (+27 gene sets). Gene sets derived from the Cellular Component Ontology; set names are prefixed with GOCC_.
• MF: GO Molecular function (+14 gene sets). Gene sets derived from the Molecular Function Ontology; set names are prefixed with GOMF_.

These updates were generated in accordance with the procedure described in the GO release notes for MSigDB 7.0.

CHIP file updates#

• MSigDB 2026.1.Mm gene annotations and gene mapping CHIP files have been updated to data from Ensembl 115.
• Gene orthology annotations for mapping human and rat genes to their best match mouse orthologs have been updated to Alliance of Genome Resources orthology database release 8.1.0 (2026-04-18)