Stomach adenocarcinoma (STAD), thyroid carcinoma (THCA), HNSCC, lung squamous cell carcinoma (LUSC), liver hepatocellular carcinoma (LIHC), esophageal carcinoma (ESCA), colon adenocarcinoma (COAD), and cholangiocarcinoma (CHOL) all showed considerably higher DKK1 expression. This evidence concerns the gene DKK1 and head and neck squamous cell carcinoma.