This is entirely consistent with the previously reported observation of direct fibroblast‐PDAC tumor cell contact.[33] However, compared to the PDAC study,[33] our data showed that both PanIN cells and surrounding fibroblasts express Activin A (Figure 5I; Figure S17, Supporting Information), suggesting that pancreatic cells with KrasG12D/+/Muc4 overexpression may secrete a small amount of Activin A to initially activate/recruit fibroblasts. This evidence concerns the gene MUC4 and neoplasm.