PGAM4 (phosphoglycerate mutase family member 4) is an X-linked retrogene that catalyzes the interconversion of 2-phosphoglycerate and 3-phosphoglycerate, a crucial step in glycolysis 1. The gene is predominantly expressed in testicular tissue, particularly in post-meiotic spermatids and spermatozoa, localizing to the sperm flagellar principal piece 1. PGAM4 plays a fundamental role in male reproduction; a G75C polymorphism associated with male infertility reduces enzymatic activity both in vitro and in vivo, present in 4.5% of infertile patients 1. However, in a Chinese Han population, the G75C polymorphism showed no significant association with non-obstructive azoospermia 2. Beyond reproduction, PGAM4 is upregulated in glioma and lung cancer, where it promotes cell viability, proliferation, and glycolytic activity 345. PGAM4 silencing in glioma cells suppresses glycolysis and chemoresistance to temozolomide 3, suggesting therapeutic potential in cancer treatment. The gene appears regulated by EP300-mediated histone acetylation modifications 3. Complete deletion of PGAM4 does not impair male fertility in carriers, indicating functional redundancy in this context 6.