The testis and spermatogenesis cell apoptosis related gene 1 (TSARG1) protein, also known as SPATA3, is highly expressed in testis, and to a lower extent in other tissues. SPATA3 contains a highly conserved J domain, which is present in all DnaJ-like proteins, and is thus a novel member of the HSP40 protein family. SPATA3 is thought to be involved in apoptosis of spermatogenic cells.Synonyms: Spermatogenesis associated protein 3, TSARG1, testis and spermatogenesis cell apoptosis related gene 1