ACTRT2 (actin related protein T2) is a cytoskeletal protein that plays crucial roles in male fertility and sperm function. ACTRT2 interacts with other actin-related proteins (ACTRT1, ACTL7A, ACTL9) to form a multimeric complex that localizes to the subacrosomal region of spermatids, which is essential for maintaining the acrosome-nucleus junction 1. The protein is specifically localized in the post-acrosomal region and middle piece of human spermatozoa, where it contributes to sperm motility regulation 2. Functionally, ACTRT2 appears critical for proper spermatogenesis and sperm quality, as decreased expression is associated with obesity-induced asthenozoospermia and reduced sperm motility 2. Heat-induced male infertility also involves downregulation of ACTRT2 along with other sperm motility-related proteins, suggesting its importance in maintaining normal sperm function under stress conditions 3. Beyond reproductive biology, ACTRT2 has been implicated in disease contexts including tick-borne encephalitis susceptibility 4 and T-cell acute lymphoblastic leukemia prognosis 5. The protein has also been identified as a methylation biomarker for prostate cancer detection 6, indicating broader roles in cellular regulation and disease processes.