CD40 and neoplasm: Similar results were observed in KPC mice treated with gemcitabine and the CD40 agonist FGK45.127 In an interesting mechanistic twist, murine studies in KPC mice revealed macrophages, rather than T cells, as indispensable for FGK45-induced tumor regression, as this CD40 agonist converted the cytokine profile and activity of macrophages to elicit stromal degradation and lysis of pancreatic tumor cells127 (figure 3).