Especially for PTPN9, its expression level is higher in PAAD with a fold change of 2.229 in Iacobuzio-Donahue dataset, the fold change of expression level in pancreatic ductal adenocarcinoma is 1.664 in Grutzmann dataset, and the fold change in pancreatitis is 2.697 in Logsdon dataset versus normal samples. Here, PTPN9 is linked to pancreatic ductal adenocarcinoma.