The ALT levels steadily increased over 4 weeks to 1643 IU (46.94 x ULN; grade 4) despite mycophenolate (Figure 2). Viral serology was negative for Hepatitis A (IgM), Hepatitis B (Core Ab, Surface Ab), Hepatitis C, and HIV, and the autoimmune panel was negative for anti-mitochondrial antibody (AMA), anti-nuclear antibody (ANA), and liver-kidney microsomal antibodies (LKMA). The liver MRI was reported as normal; hence, an ultrasound-guided liver biopsy was performed by interventional radiology. The gene discussed is GPT; the disease is hepatitis A virus infection.