The vast majority of these tumors (95%) are benign; in a number of cases germ cell tumors may be associated with elevated tumor markers including human chorionic gonadotropin (HCG), alfa-fetoprotein (AFP), and the recently introduced embryonic serum microRNAs (MiRNA), which helps in the diagnosis and monitoring of such tumors [92]. The gene discussed is AFP; the disease is testicular germ cell tumor.