The association of infiltrating CD8 + cytotoxic T cells, as well as that of CD3 + T cells, with favorable prognosis has been widely demonstrated in cancers with different histological features and anatomical location, in both primary and metastatic settings, including melanoma, most squamous cell carcinomas, large cell lung cancer and several types of adenocarcinoma51–54. Here, CD8A is linked to squamous cell carcinoma.