P2RX4 and pancreatic ductal adenocarcinoma: These effects on cell proliferation are in accordance with those observed in pharmacological assays performed on P2Y2R in gastric cancer [14], pancreatic ductal adenocarcinoma [47], esophageal [48], breast carcinoma [49], and on P2X4R in gastric [14], breast [50], and prostate cancer [51].