Might have a role in spermatogenesis. Associated with the acrosome during post-meiotic stages of spermatogenesis. Appears to migrate to the nucleus during the final step of spermiogenesis. Expressed strongly in testis, where it is specifically detected in haploid germ cells (at protein level). Also expressed strongly in skeletal muscle. Detected from postnatal day 15 onwards, with high levels of expression by postnatal day 28.