AMH and Leydig cell tumor: All this being said, the expression of anti-Müllerian hormone (AMH) in Leydig cells remains a bit of an anomaly since AMH expression has traditionally been associated with Sertoli cell tumors rather than Leydig cell tumors [18] and AMH expression in normal cells is widely believed to be confined to Sertoli cells and not to Leydig cells [34–37].