Recent findings unveiled that high serum levels of the molecular marker microRNA 371 correlate with the clinical stage and metastasis of seminomas (tumor of the testis germ cells) and nonseminomas. The expression of miR-371a-3p was evaluated in a cohort of patients with stage IIA/B seminoma and nonseminoma. Expression of miR-371a-3p was found to be positive in all 12 metastatic patients with seminoma or nonseminoma and was negative in 3 out of 4 nonmetastatic cases.