GALNT3 is highly expressed in the testis; one case report described a boy with testicular microlithiasis associated with oligozoospermia.(61) The finding that common variants in GALNT3 on GWAS appear to be protective against type 2 diabetes also raises the concern that inactivating GALNT3 may increase the risk of developing this condition. This evidence concerns the gene GALNT3 and type 2 diabetes mellitus.