H3C12 (H3 clustered histone 12) is a histone variant located on chromosome 6 with emerging roles in disease pathogenesis. H3C12 was identified as a core differentially expressed gene in chr6 venous ulcer tissues, where it is overexpressed in untreated ulcers and downregulated following ultrasound therapy 1. The gene is associated with vascular pathologies including thrombophlebitis, phlebitis, vascular malformations, and inflammatory responses 1. In cancer contexts, H3C12 interacts with histone-modifying proteins including SETD7 and other histone variants (H3-3B, H3-4, H3C13), suggesting involvement in epigenetic regulation through FOXO signaling pathways relevant to colorectal cancer progression 2. Additionally, H3C12 was identified among key genes in hepatocellular carcinoma pathogenesis through multi-omics analysis 3. In oral squamous cell carcinoma, H3C12 demonstrated significant prognostic value for radiotherapy resistance in multivariate Cox regression analysis, indicating its relevance to treatment outcomes 4. These findings suggest H3C12 functions as a histone regulatory protein implicated in vascular inflammation, cancer progression, and radiation resistance, though its specific molecular mechanisms remain incompletely characterized.