ISL1 and pancreatic ductal adenocarcinoma: We observed robustly increased expression of neuroendocrine and PanNET marker genes, including Insulin, Chromogranin A, Synaptophysin, PAX6, ISL1, SSTR2, ASCL1, and NCAM1, in MAP tumors compared to normal wildtype pancreas or pancreatic ductal adenocarcinoma biopsies from KrasG12D; p53Lox; Ptf1-Cre (KPC) mouse model (Fig. 3A).