Tumour antigen-induced T cell exhaustion — the archenemy of immune-hot malignancies

Two recent studies addressed the functional properties and clinical significance of tumour antigen-specific effector T cells in human melanomas and lung carcinomas using single-cell strategies. Herein, we discuss their findings, which expand our understanding of T cell alterations in the tumour microenvironment and demonstrate that CD8+ T cell exhaustion is mediated by exposure to tumour cell-specific antigens and is associated with a tissue-resident memory phenotype.