For this purpose, we used conditional null alleles of Palb2 (Palb2flox2-3) [31], Brca1 (Brca1flox2) [29] and Brca2 (Brca2flox3-4) [30] in combination with the well characterized Pdx1-Cre transgene that has been extensively used for modeling pancreatic ductal adenocarcinoma (PDAC) in mice. The gene discussed is BRCA1; the disease is pancreatic ductal adenocarcinoma.