According to the literature, since 1995, Kass and coworkers [121] identified some of the indications to treat varicocele: abnormality of semen analysis; left testicular volume at least 3 mL lower than that of the right; secondary sexual hormone axis hyper-function (i.e., LH/FSH response to Gn-RH); presence of bilaterally palpable varicoceles or large symptomatic varicocele. The gene discussed is PLOD1; the disease is varicocele.