Highlights a study by Zhang Wei-yuan and Yen Guo-lai that determined serum S P1 (pregnancy specific beta1 glycoprotein), hPL (human placental lactogen) and beta-hCG (beta-human chorionic gonadotropin) in patients with choriocarcinoma, invasive mole, and hydatidiform mole by radioimmunoassay. Comparison with those in normal males, non-pregnant women and normal pregnant women. Study methods and results .