Since a high overall CD8+ T cell infiltration accompanied high frequencies of CD8High T cells, which implies a favoured prognosis in the individual patient,33 and the number of tumour‐infiltrating CD8Low T cells also correlated with enhanced cancer progression in human breast cancer patients (Figure 5), we suggest that the occurrence of CD8Low and CD8High T cells may be an important predictor or indicator of the patient prognosis. The gene discussed is CD8A; the disease is breast cancer.