Apart from hepatotoxicity caused by immunosuppressant drugs, other causes of liver enzyme elevation among these 42 patients included: hepatitis consequent to HBV reactivation; transient and spontaneous ALT elevation; and chronic liver disease (operationally defined as persistent ALT elevation without, or after, discontinuing hepatotoxic drugs and with no evidence of HBV reactivation). The gene discussed is GPT; the disease is hepatitis A virus infection.