Highly expressed in seminiferous tubes in testis. Highly expressed in spermatids, barely detectable in late pachytene spermatocytes, and not detectable in spermatogonia. Detected at intermediate levels in pancreas and lymph nodes, and at much lower levels in spleen, peripheral blood leukocytes, skeletal muscle, liver, lung, placenta, brain and heart. Belongs to the GOLGA6 family. Maps to a duplicated region on chromosome 15; the gene is present in at least 4 almost identical copies.