Whilst not yet supported by evidence of OS improvement, dual CTLA-4/PD-1 blockade might also be beneficial, given the different and alternative role of the two biologic axes within the cancer immunity cycle, as CTLA-4 is a key driver in downregulation of tumour-antigen presenting cells and in T-regs enhancement, whereas PD-1/PD-L1 mainly impairs the efficiency of the CD8 + CTL response. This evidence concerns the gene CTLA4 and cancer.