In particular, checkpoint blockade strategies targeting cytotoxic T-lymphocyte associated protein 4 (CTLA-4) or the programmed cell death protein 1/programmed cell death ligand-1 (PD-1/PD-L1) axis are used in many different cancers including melanoma, non-small lung cancer (NSCLC), renal cell carcinoma, bladder cancer, Hodgkin lymphoma, head and neck cancer, squamous cell carcinoma and Merkel cell carcinoma, among others. This evidence concerns the gene CTLA4 and head and neck cancer.