DAZ1 (deleted in azoospermia 1) is a Y chrY-encoded RNA-binding protein essential for spermatogenesis. Located in the AZFc region of Yq11.2, DAZ1 functions as a master translational regulator that interacts with PABPC1 through its DAZ repeat domain to control global translation of cell proliferation-related mRNAs 1. This interaction is critical for maintaining spermatogonia proliferation and enabling germ cell progression through meiosis to produce haploid gametes. DAZ1 expression is specifically active in testicular tissue through differential methylation of its promoter region—remaining unmethylated in sperm while methylated in somatic cells 2. Clinically, DAZ1 deletions are a significant risk factor for male infertility. Partial DAZ1/DAZ2 deletions are associated with azoospermia and oligozoospermia, with a 2.58-fold increased infertility risk overall 3, and account for approximately 8% of idiopathic oligozoospermia cases 4. Loss of DAZ1 results in defective proliferation of c-KIT-positive spermatogonia and spermatogenic failure 1. DAZ1 expression patterns in testicular biopsies can serve as molecular markers for predicting sperm retrieval success in azoospermic patients 5.