Biologically, the patient had impaired coagulation tests (prothrombin concentration of 51%), persistently increased liver enzymes together with hyperbilirubinemia, and a viral serology (for an easier read, all serological testing and molecular testing is presented in Table 1) consistent with acute hepatitis due to both HBV and HEV (positive IgM HVEAb (antibodies) and IgM HBsAb), indicating possible co-infection. The gene discussed is CD40LG; the disease is Hyperbilirubinemia.