CTLA4 and neoplasm: The combination of cytotoxic T-lymphocyte antigen 4 (CTLA-4) and programmed death-1 (PD-1) blockade has been linked to better antitumor responses; in this context, it has been shown that ipilimumab, a monoclonal anti-CTLA4 antibody, increases tumor-infiltrating T cells and up-regulates the PD-1/PD-L1 inhibitory pathway in a compensatory fashion, implying that combination therapy may be very effective [35].