ACRV1 encodes SP-10, an acrosomal vesicle protein that plays a critical role in mammalian spermatogenesis and sperm function. The protein is specifically expressed in the testis, first appearing in round spermatids and localizing to the acrosomal matrix and membranes of developing and mature sperm 1 2. ACRV1 expression begins around day 35 of mouse postnatal development and is restricted to round and elongated spermatids 2. The gene's transcriptional regulation involves precise spatiotemporal control mechanisms, including RNA polymerase II pausing in spermatocytes mediated by TDP-43, ensuring proper expression timing during spermatogenesis 3 4. Beyond reproduction, recent studies have identified an oncogenic role for ACRV1 in ovarian cancer, where it promotes aerobic glycolysis and tumor progression through the PI3K/AKT signaling pathway when transcriptionally activated by ZNF280A 5. The protein serves as a valuable molecular marker for staging seminiferous epithelium cycles across mammalian species 6 and has been investigated as a potential contraceptive vaccine target due to its tissue specificity and role in sperm-egg interactions 1. The single-copy gene is located at chromosome 11-q24 7.