This gene belongs to the VCX/Y gene family, which has multiple members on both X and Y chromosomes, and all are expressed exclusively in male germ cells. The X-linked members are clustered on chromosome Xp22, and the Y-linked members are two identical copies of the gene within a palindromic region on chromosome Yq11. The family members share a high degree of sequence identity, with the exception that a 30-nt unit is tandemly repeated in X-linked members but occurs only once in Y-linked members. The VCX gene cluster is polymorphic in terms of copy number; different individuals may have a different number of VCX genes. This family member, as represented by the reference genome allele, contains 14 copies of the 30-nt repeat unit. VCX/Y genes encode small and highly charged proteins containing putative bipartite nuclear localization signals. Although the exact function of this family member has yet to be determined, a role in mRNA stability regulation can be inferred from the ability of the highly similar family member, VCX-A, to inhibit mRNA decapping. A possible role in the regulation of ribosome assembly during spermatogenesis has also been suggested. [provided by RefSeq, Aug 2010].