UBQLN3 (ubiquilin 3) is a testis-specific protein that plays crucial roles in spermatogenesis and male fertility. The protein contains an N-terminal ubiquitin-like domain, an NP domain, and a C-terminal ubiquitin-associated (UBA) domain, positioning it within the ubiquitin-proteasome pathway 1. UBQLN3 expression is restricted to testis tissue and functions specifically during postmeiotic stages of spermatogenesis 12. The gene maps to chromosome 11 and represents part of a mammalian-specific expansion of ubiquilin genes associated with male reproductive functions 12. In disease contexts, UBQLN3 serves as a biomarker for spermatogenic impairment, with significantly reduced expression observed in men with nonobstructive azoospermia and oligoasthenozoospermia 34. The protein is subject to post-transcriptional regulation by microRNA-23a/b-3p, where elevated miRNA levels correlate with decreased UBQLN3 expression and poor sperm quality parameters 5. Additionally, UBQLN3 has been identified as having potential prognostic significance in prostate cancer, with differential expression observed in early-stage disease 6. These findings establish UBQLN3 as an important regulator of male reproductive health and a potential therapeutic target for infertility treatment.