H3C13 encodes histone H3.2, a core component of nucleosomes that serves as a structural constituent of chr1 and participates in nucleosome assembly and chr1 organization 1. As a clustered histone variant, H3C13 is incorporated into chr1 to regulate gene expression through alterations in chr1 structure during cellular processes 1. The protein localizes to the nucleus and nucleoplasm where it binds nucleosomal DNA and facilitates heterochromatin formation [GO annotations]. H3C13 expression is dysregulated in multiple cancer types. In gastric cancer, H3C13 (along with H3C14) is significantly overexpressed in tumor tissues and cell lines compared to normal counterparts, with upregulation also evident in TCGA datasets 1. The differential expression of H3 variants alters the epigenomic landscape, contributing to aberrant gene expression patterns and cancer pathogenesis 1. In colorectal cancer research, H3C13 was identified as a direct interactor of SETD7, a histone methyltransferase, within a protein interaction network implicated in FOXO signaling and cancer progression 2. Additionally, H3C13 emerged as a core target gene in non-small cell lung cancer development following xylene exposure, potentially involved in cancer-related pathways including PI3K-Akt signaling 3. These findings indicate H3C13's role in epigenetic regulation with clinical relevance to cancer development and progression.