Lactic dehydrogenase (LD), an enzyme which can catalyze the conversion of lactate to pyruvate, has been demonstrated in the serum of animals1-3and humans.4-6Hill and Levi4studied 51 patients with neoplastic disease, only 2 of whom failed to exhibit elevated serum levels of this enzyme. Bierman and his associates5found elevated levels in 121 out of 132 patients with carcinoma. In an earlier report7from this laboratory, elevated LD levels were noted in half of 30 patients with carcinoma. Serum glutamic oxalacetic transaminase (GOT), an enzyme which catalyzes the reversible transfer of an amino group from aspartate to α-ketoglutarate has also been studied in neoplastic disease. Wróblewski and LaDue8reported elevated serum GOT levels in 23 of 25 patients with proved carcinomatosis involvement of the liver. Subsequently, these workers reported elevations of GOT in 75 out of 100 patients with primary hepatoma or