FAP and pancreatic adenocarcinoma: As shown in Fig. 1a, we found that the expression of ACTA2, fibroblast activation protein (FAP), platelet-derived growth factor receptor-α/β (PDGFRα/β), and S100A4 (widely used as markers to define CAFs) were markedly overexpressed in PAAD tissues compared with the paired normal tissues (http://gepia.cancer-pku.cn).