In particular, centrilobular confluent necrosis and plasmacytosis in ICI-induced liver injury were markedly less common and milder than in autoimmune hepatitis; liver injury caused by immunotherapy was associated with markedly fewer CD20+ and CD4+ lymphocytes than autoimmune hepatitis; and eosinophilic infiltration was less common and there were fewer CD20+ and CD4+ lymphocytes in immunotherapy-triggered hepatitis than in idiosyncratic drug-induced liver injury. This evidence concerns the gene CD4 and hepatitis A virus infection.