CDH2 and pancreatic ductal adenocarcinoma: In the progression of pancreatic ductal adenocarcinoma (PDAC), the oxidative pentose phosphate pathway orchestrated by 6‐phosphogluconate dehydrogenase facilitates the reprogramming of histone H3K9, propelling the transcription of n‐cadherin and promoting distant metastasis mediated by n‐cadherin.110