CSAD and hepatocellular carcinoma: In Kishimoto's study [35], overexpression of cysteine sulfinic acid decarboxylase (CSAD) at mRNA and protein levels was observed in the precancerous liver in rats with HCC, and the auto-antibody to CSAD was also detected in sera of the HCC-bearing rats with a much higher level than that in normal rats, proposing that the high level of CSAD autoantibody resulted from increased CSAD gene or protein expression in the liver of HCC rats.