Using the TCGA database (https://www.cancer.gov/) and GEPIA2 database (http://gepia2.cancer-pku.cn/) 29, we found that CDK1 was generally upregulated in digestive tumors (liver hepatocellular carcinoma, cholangiocarcinoma, pancreatic adenocarcinoma, stomach adenocarcinoma, esophageal carcinoma and colon adenocarcinoma) (Figure S5A) and closely related to the poor prognosis of hepatobiliary and pancreatic tumors (Figure S5B-C). Here, CDK1 is linked to digestive system neoplasm.