CD274 and anal carcinoma: Blockade of the PD-1/PD-L1 pathway has also become a major focus in anticancer drug development, with the US Food and Drug Administration granting approval of several antibodies blocking immune checkpoints for the treatment of advanced melanoma, Hodgkin's lymphoma, and lung and bladder cancer.8, 9, 10 Blockade of the PD-1/PD-L1 pathway is also being actively examined in a number of cancers that are often associated with chronic viral infections, such as hepatocellular carcinoma (NCT01658878), cervical cancer (NCT02291055, NCT02164461) and anal cancer (NCT01671488).