(A–B) Tumors from LSL-KrasG12D/+; Trp53fl/fl; Pdx1-Cre; LSL-tdTomato (KP-/-CT) mice were stained with antibodies against RFP (red) and (A) α-SMA (green), a fibroblast marker, or (B) CK19 (green), a cancer cell marker. The gene discussed is PDX1; the disease is cancer.