Indeed, provided that peptide presentation by MHC class I to be recognized by the T-cell receptor of CD8+T leads to the initiation of an adaptive immune response [118] decisive in the recognition and elimination of cancer cells, alterations affecting MHC-I transcription and expression will have an important impact on anti-PD-1/PD-L1 therapies and justify the need to find strategies that permit the recovery of MHC-I expression. The gene discussed is PDCD1; the disease is cancer.