A further analysis revealed that, in the CD13+/CD90− fraction, the modulatory subunit of the glutamate-cysteine ligase (GCLM), an enzyme catalyzing the rate-limiting step of GSH synthesis, was overexpressed compared to the CD13+/CD90+, CD13−/CD90+, and CD13−/CD90− fractions of PLC/PRF/5 and primary HCC cells. Here, ANPEP is linked to hepatocellular carcinoma.