TBPL2 (TATA-box binding protein like 2) is a vertebrate-specific transcription factor that plays critical roles in reproductive development and cell differentiation. As a member of the TBP family, TBPL2 shares 95% sequence similarity with TBP's core domain and binds to TATA-box sequences, interacting with general transcription factors including TFIIA and TFIIB 1. The protein functions in complex with TAF3 to regulate myoblast differentiation into myocytes, replacing TFIID at specific promoters during early differentiation 2. TBPL2 shows higher expression in gonads compared to other organs, suggesting important functions in gametogenesis 3. Clinically, TBPL2 mutations are strongly associated with female infertility. A rare stop-gained mutation (p.Arg299Ter) shows exceptionally high penetrance for infertility with an odds ratio of 650, and homozygous carriers average only 0.16 offspring compared to 1.75 in other genotypes 4. Additional studies confirm TBPL2's involvement in oocyte maturation and early embryonic development, with pathogenic variants identified in infertile women undergoing assisted reproductive therapy 56. The gene has evolved specifically within vertebrates and represents a key regulator of reproductive success and cellular differentiation processes 3.