CD4 and neoplasm: In the derivation cohort, high tumour PD-L1 expression (p = 0.003), high infiltration of stromal CD8+ immune cells (p = 0.035), high infiltration of stromal CD3+ immune cells (p = 0.017), high infiltration of stromal CD4+ immune cells (p = 0.010), both high infiltration of stromal and tumour CD8+ immune cells (p < 0.0001), both high infiltration of stromal PD-1+ and CD8+ immune cells (p = 0.023) and both high infiltration of stromal PD-L1+ and CD8+ immune cells (p = 0.021) were associated with longer OS (Fig. 2a–g, Table 3).