Among the top ten cancer types contributing to cancer-related mortality, DDB2 was significantly overexpressed in tumor tissues compared to matched normal tissues in lung squamous cell carcinoma (LUSC), liver hepatocellular carcinoma (LIHC), cholangiocarcinoma (CHOL), colon adenocarcinoma (COAD), head and neck squamous cell carcinoma (HNSC), stomach adenocarcinoma (STAD), and esophageal carcinoma (ESCA), as revealed by Gene Expression Profiling Interactive Analysis (GEPIA) 32 (Figure 1D and Supplementary Figure S2A) and in TNMplot 33 (Supplementary Figure S2B). This evidence concerns the gene DDB2 and cholangiocarcinoma.