CCNA1 (cyclin A1) is a cell cycle regulator primarily functioning in meiotic progression and mitotic cell cycle control. It controls transitions at G1/S and G2/M checkpoints 1, with particularly high expression in late spermatocytes where it is essential for meiotic division. CCNA1 is regulated transcriptionally by factors including RNF6, which binds its promoter in gastric cancer cells 2, and by TRIM13-mediated ubiquitination that suppresses self-renewal in acute myeloid leukemia 3. Clinically, CCNA1 is highly relevant to cancer development through epigenetic silencing. Aberrant CCNA1 promoter methylation occurs significantly more frequently in cancer tissues than normal tissues across multiple populations 45. HPV-16 E7 oncoprotein drives CCNA1 methylation by forming complexes with DNA methyltransferase 1 at the CCNA1 promoter, suppressing expression in cervical and head-neck cancers 6. CCNA1 promoter methylation demonstrates high specificity (99.3-99.5%) as a biomarker for detecting high-grade cervical intraepithelial lesions in HPV-positive women 78, with positive predictive values of 80-89% for identifying significant cervical pathology. These findings suggest CCNA1 methylation serves as a valuable non-invasive biomarker for cancer risk stratification and early lesion detection.