H4C8 (H4 clustered histone 8) is a histone gene located on chromosome 6 with emerging roles in degenerative and neurological diseases. At the molecular level, H4C8 expression is regulated by lactylation-related pathways and DNA methylation, positioning it within metabolic signaling cascades affecting cellular function 1. H4C8 is positively correlated with intervertebral disc degeneration (IVDD) risk, suggesting that elevated expression contributes to disc pathology through lactylation-driven mechanisms 1. In Parkinson's disease, H4C8 expression is significantly elevated in both substantia nigra tissue and peripheral blood mononuclear cells of patients compared to controls, demonstrating coordinated dysregulation across central and peripheral compartments 2. Within the NOTCH signaling pathway, H4C8 expression changes show strong discriminatory ability to separate PD patients from controls, indicating potential diagnostic utility 2. Additionally, H4C8 expression correlates with COVID-19 disease severity in infected patients 3. These findings suggest H4C8 functions as a biomarker for neurodegenerative and infectious diseases, with expression patterns potentially reflecting underlying pathological processes. Further mechanistic studies are needed to establish whether H4C8 plays a causative or consequential role in disease pathogenesis versus serving primarily as a disease indicator.