A ‘cold’ tumour is a common resistance phenotype observed across solid cancers.70 The classification of hot and cold tumours relies partly on the degree and localisation of infiltrating CD8+ T cells, as well as the composition of the TME.71 Hot tumours are characterised by high infiltration of non-exhausted T cells, especially CD8+ T cells,71 whereas cold tumours lack T-cell infiltration and fail to induce T-cell priming (Fig. 6). Here, CD8A is linked to neoplasm.