Cystic fibrosis (CF) is the most common life-limiting recessive genetic diseaseamong Caucasians caused by mutations of the cystic fibrosis transmembraneconductance regulator (CFTR) with over 95% male patients infertile.However, whether CFTR mutations could affect spermatogenesis and result inazoospermia remains an open question. The gene discussed is CFTR; the disease is cystic fibrosis.