Abstract
Summary: γ-glutamyl transpeptidase of human serum studied by starch gel electrophoresis and Sephadex filtration is not homogenous. Excepting liver cirrhosis no distinct distribution pattern of activity specific to any hepatobiliary disease or other internal diseases were found. Studies of GGTP heterogeneity seems to be of no great clinical significance in the differential diagnosis of hepatic or extrahepatic diseases.