TPPP2 (tubulin polymerization promoting protein family member 2) is a testis-specific protein that plays a crucial role in male fertility by regulating sperm development and motility. Unlike other TPPP family members, TPPP2 lacks microtubule bundling activity but functions as a probable regulator of microtubule dynamics essential for sperm function 1. The protein is exclusively expressed in elongating spermatids during stages IV-VIII of spermiogenesis and localizes to the middle piece of mature sperm tails in the epididymis 2. TPPP2 is critical for proper sperm formation, as its deficiency in knockout mice results in oligoasthenozoospermia characterized by decreased sperm count and motility 2. The mechanism involves regulation of mitochondrial structure and function, as TPPP2-deficient sperm exhibit irregular mitochondria with impaired cristae, reduced ATP levels, and decreased membrane potential 2. TPPP2 may interact with eEf1b (eukaryotic translation elongation factor 1 beta), potentially affecting protein translation during spermiogenesis 2. Additionally, TPPP2 participates in a cytoplasmic protein network with MNS1, RSPH1, ZPBP1, and SPACA1 during sperm development 3. Clinically, TPPP2 serves as a potential biomarker for non-obstructive azoospermia and represents a candidate gene for male infertility diagnosis 4.