PARP8 (poly(ADP-ribose) polymerase family member 8) is a mono-ADP-ribosyltransferase that mediates mono-ADP-ribosylation of target proteins and exhibits NAD+-dependent enzymatic activity. The protein localizes to cellular membranes, nuclear envelope, and endoplasmic reticulum, where it participates in the unfolded protein response and functions as a protein kinase activator. PARP8 demonstrates significant disease relevance across multiple pathological conditions. In cancer, PARP8 deletions are associated with prostate cancer progression and poor prognosis 1, while the gene serves as a component of prognostic signatures in uveal melanoma 23. PARP8 also functions as a biomarker for ulcerative colitis, with elevated expression correlating with neutrophil and M1 macrophage infiltration in inflammatory bowel disease 4. In ocular disease, PARP8 represents a novel susceptibility gene for high/extreme myopia, where reduced expression mediated by hsa-miR-410-3p contributes to myopia pathogenesis 5. Additionally, PARP8 shows signatures of positive selection in human immunity genes, potentially related to pathogen adaptation 6, and serves as a biomarker distinguishing active from latent tuberculosis in children 7. The gene's involvement in immune responses, DNA repair, and cellular stress responses underlies its clinical significance across these diverse pathological contexts.