Similarly, ablation of Dhh in mice leads to severe testis dysgenesis including apolar Sertoli cells, anastomotic testis cords, a reduced number of fetal Leydig cells and insufficient production of androgens, resulting in male infertility, hypogonadism, underdeveloped male accessory glands and feminized external genitalia [24], [25], [26]. The gene discussed is DHH; the disease is male infertility.