CTLA4 and hepatocellular carcinoma: In 2013, a prospective study evaluated the use of tremelimumab, a cytotoxic T-lymphocyte-associated antigen 4 inhibitor, in 22 patients with chronic hepatitis C virus (HCV) infection and hepatocellular carcinoma (HCC).6 The results showed some transient elevation of transaminases but no HCV infection exacerbation or hepatitis flare.