CD40 and neoplasm: Interestingly, it was shown that the tumor-derived cytokines are able to activate the p38 MAPK pathway and STAT3 signaling in DCs, leading to lower expression levels of costimulatory molecules (i.e., CD40, CD80), activation markers (e.g., HLA-DR) and CD1a, and functionally abnormal DCs (Figure 3) (15).