PGK2 is a form of phosphoglycerate kinase unique to spermatozoa. The autosomal PGK2 gene lacks introns and contains characteristics of a processed gene. The conservation of function in this processed PGK2 gene and its tissue-specific expression in spermatogenesis suggests that it exists as a compensatory response to the inactivation of the X-linked PGK1 gene in spermatogenic cells before meiosis.
