AFP and beta subunit chorionic gonadotropin (hCG) levels by EIA methods are elevated in certain gonadal tumors. In general, pure seminomas fail to produce AFP, whereas hCG production in seminoma ranges from 0%–37%. Some 70% or more of patients with embryonal cell carcinoma and malignant teratoma have elevated AFP levels, and 40%–60% or more have elevated hCG levels. Eighty-five percent or more patients have elevated levels of one or both. Elevation of AFP by immunoassay occurs in hepatoma (70%–90%,Chapter 20) and has also been reported in up to 18% of patients with gastric carcinoma, up to 23% of those with pancreatic carcinoma, and occasionally in patients with lung carcinoma or other tumors, mostly in low titer. Elevated AFP level is also reported in up to 30% of patients with acute and chronic active hepatitis. Elevated hCG level is found in choriocarcinoma or hydatidiform mole (Chapter 32) and has also been reported in low titer with a small number of various other neoplasms, notably gastric, hepatic, pancreatic, and breast carcinoma. It has even been detected in a few patients with melanoma and myeloma (again, usually in very low titer).