We propose that serum AMH in infertile men is a marker for Sertoli cell health and function that ultimately, may be used to select the infertile men who will benefit from a Sertoli cell stimulator such as FSH, clomiphene or as recently suggested a receptor activator of nuclear factor kappa-β ligand (RANKL) inhibitor [28]. The gene discussed is AMH; the disease is Infertility.