CHEK1 and pancreatic adenocarcinoma: In our study, WGCNA was used to identify the green module (involving 85 genes) that was related to PAAD OS, and 4 genes (AURKA, MELK, KIF23, and CHEK1) were found specifically expressed in PAAD and played an important role in the development of PAAD, which may become the prognostic markers.