[3][4] "Temporally regulated transcription and translation of several testis-specific genes is required to initiate the series of molecular and morphological changes in the male germ cell lineage necessary for the formation of mature spermatozoa.

The SPANX genes encode differentially expressed testis-specific proteins that localize to various subcellular compartments.

This particular gene maps to chromosome X in a head-to-head orientation with SPANX family member A2, which appears to be a duplication of the A1 locus.

Based on its association with these poorly characterized regions of the sperm nucleus, this protein provides a biochemical marker to study unique structures in spermatazoa [sic] while attempting to further define its role in spermatogenesis.

This article on a gene on the human X chromosome and/or its associated protein is a stub.