SHBG and spermatogenic failure: Previous reports have identified several autosomal gene mutations and polymorphisms that affect male fertility, e.g., the cystic fibrosis transmembrane conductance regulator (CFTR) gene encoding a glycosylated transmembrane chloride channel affecting the vas deferens (for review, see [4]), the SHBG gene encoding the glycoprotein sex hormone-binding globulin (SHBG), or genes associated with spermatogenic failure (for review, see [5]).