CD8A and neoplasm: In this study, we defined OSCC samples with low tumoural PD-L1 and low stromal CD8+TILs as cold tumours, which reportedly correlates with the low anti-tumour immune reactivity.15,16 Patients with a cold tumour markedly correlated with the Y–K classification, high 18F-FDG-uptake, high expression of GLUT1, low levels of TILs and negative expression of E-cadherin when compared with those of others (Table 1).