Consistent with other bioinformatic analysis, a significant overexpression of DKK1 was revealed in head and neck squamous cell carcinoma (HNSC), pancreatic adenocarcinoma (PAAD), and lung squamous cell carcinoma (LUSC), with DKK1 overexpression being associated with shorter disease-free survival (DFS) (42). Here, DKK1 is linked to pancreatic adenocarcinoma.