CSNK2A2 encodes the catalytic alpha 2 subunit of casein kinase 2 (CK2), a constitutively active serine/threonine kinase that phosphorylates substrates with acidic residues C-terminal to target sites 1. As a regulatory hub, CSNK2A2 coordinates multiple cellular processes including cell cycle progression, transcription, and apoptosis 23. The protein functions in DNA damage responses by phosphorylating repair proteins (MDC1, RAD9A, RAD51) and promoting their recruitment to damage sites 456. During mitosis, CSNK2A2 participates in p53-dependent spindle assembly checkpoint maintenance 78. CSNK2A2 also suppresses autophagy by phosphorylating TRIM family proteins, limiting autophagosome formation and viral restriction 9. Clinically, CSNK2A2 overexpression associates with poor prognosis in hepatocellular carcinoma through NF-κB pathway activation 10, and elevated expression predicts shorter survival in lung squamous cell carcinoma 11. A CSNK2A2 intronic variant (rs74019828) associates with leukocyte telomere length in South Asian populations 12, while variants in CSNK2A2 (rs2731783) show genome-wide significant association with systemic lupus erythematosus, with effects mediated through B-lymphocyte expression 13. DNA methylation at CSNK2A2 (cg01248361) responds to PM2.5 exposure and potentially mediates pollution-induced aging 14.