CD40 and leukemia: Previous studies have shown that the in vivo engagement of PD-L1 blockade, CD40 ligation, and STING agonist are capable of enhancing leukaemic antigen-specific T-cell stimulatory capacity and inducing anti-leukaemic therapeutic effects in C1498 leukaemia models.26–28 However, these studies use highly immunogenic foreign antigen-expressing C1498 cells to validate antigen-specific anti-tumour CD8 T-cell responses and thus have potential limitations of using artificial systems.