TEX2 and Infertility: A protandrous-specific gene expressed in testis were also the Wnt8, the testis expressed sequence 2, Tex2, and the Cyp17a. Recently, studies on mice detected Cyp17 in germ cells: spermatogonia, pachytene spermatocytes, spermatids and sperm, and the loss of this enzyme is associated with sperm abnormalities and infertility.