In this study, by screening a GEO dataset containing 36 microdissected PDAC and matching normal pancreatic tissue samples, four differentially expressed K<sup>+</sup> channels (KCNJ5, KCNJ16, KCNN4 and KCNK1) were identified in PDAC. by immunohistochemical analysis of pancreatic tissue sections from Pdx1-Cre; LSL-Kras<sup>G12D/+</sup> mice (KC), Pdx1-Cre; LSL-Kras<sup>G12D/+</sup>; LSL-Trp53<sup>R172H/+</sup> mice (KPC) and human PDAC tissue microarrays, we found that Ca<sup>2+</sup>-activated K<sup>+</sup> channel KCNN4 was significantly elevated in pancreatic intraepithelial neoplasia (PanIN) and PDAC epithelia compared with untransformed pancreas tissues.