Laboratory studies include serum lactate dehydrogenase, which is an unspecific tumor mass marker elevated in 40% to 60% of all GCTs, and the specific tumoral markers alpha-fetoprotein and beta-human chorionic gonadotropin, with elevation of either or both occurring in approximately 80% of non-seminomas3 (including the current case). The gene discussed is AFP; the disease is neoplasm.