HEV RNA positive/HEV IgM and IgG negative patients (n = 10, 20.8%) were only to be found in the group of immunosuppressed patients (two patients after allogeneic stem cell transplantation, three patients after liver transplantation, one patient after kidney transplantation, one patient with overlap syndrome with primary biliary cholangitis and autoimmune hepatitis under immunosuppressive therapy, two patients with lymphoma and one patient with chronic lymphatic leukemia). The gene discussed is CD40LG; the disease is primary biliary cholangitis.