GPT and cholestasis: A 20-year-old Japanese man experienced his first cholestasis attack at the age of 17 years old with the following laboratory findings; serum total bilirubin, 16.0 mg/dL; alkaline phosphatase (ALP), 682 IU/L; GGT activity, 16 IU/L; serum aspartate aminotransferase (AST), 158 IU/L; and alanine aminotransferase (ALT), 518 IU/L (Table 1).