After day + 100, chronic hepatic GVHD is the primary cause of liver injury, occurring in about 40% of allogeneic patients.[18] Liver GVHD usually presents with progressive or sudden elevation of alkaline phosphatase and gamma glutamyl transpeptidase levels, whereas liver cGVHD affecting bile ducts and resulting in severe hyperbilirubinemia occurs less frequently. The gene discussed is GGTLC1; the disease is Hyperbilirubinemia.