CD4 and lung carcinoma: Despite this, emerging evidence has suggested that in lung cancer, these CD4+ T cells are prognostically significant, with increased tumor‐infiltrating CD4+ T cells correlated to improved survival.17 Importantly, CD4+ T cells are considered central to licensing DCs through CD40L signalling, enabling CD8+ T‐cell cross‐priming and stimulating CD8+ T‐cell memory development.19 Furthermore, recent research has demonstrated CD4+ T cells to be important in instigating recognition of neoantigens and driver mutations in human NSCLC tumors, with endogenous responses demonstrated in patients.23