CD40 and pancreatic adenocarcinoma: In pancreatic adenocarcinoma as well, CD40 expression demonstrated considerable intratumoral heterogeneity (R2 = 0.38), high concordance between serial sections (R2 = 0.94), and some correlation between expression in the tumor and stroma compartments (R2 = 0.30; Supplementary Fig. 3A-C).