ICIs are able to restore the immune response against tumor cells through the inhibition of specific immune-checkpoint receptors or ligands and consist of programmed death receptor 1/programmed death receptor ligand 1 (PD−1/PD-L1) inhibitors and cytotoxic T-lymphocyte-associated protein 4 (CTLA−4) inhibitors. Here, CTLA4 is linked to neoplasm.