Importantly, untreatable causes of male factor infertility (such as secretive azoospermia due to Sertoli cell only syndrome, or complete germinal maturative arrest, and/or genetic diseases such as karyotype alterations, Y‐chromosome microdeletions, and CFTR mutations causing secretive azoospermia) were found in only 24 patients. The gene discussed is CFTR; the disease is Sertoli Cell-Only Syndrome.