Before testing the small molecule inhibitor INCB057643 in our mouse models, we first confirmed that BRD4 is expressed in pancreatic cancer cell lines (Figure S1A,B) and the pancreas of both LSL-KrasG12D/+; Pdx-1-Cre (KC) and LSL-KrasG12D/+; LSL-Trp53R172H/+; Pdx-1-Cre (KPC) mice. This evidence concerns the gene PDX1 and familial pancreatic carcinoma.