As shown in Figure 1A, DDX21 expression levels in the tumor tissues of CHOL (cholangiocarcinoma), COAD (colon adenocarcinoma), LUSC (lung squamous cell carcinoma), ESCA (esophageal carcinoma), STAD (stomach adenocarcinoma), HNSC (head and neck squamous cell carcinoma), READ (rectum adenocarcinoma), and LUAD (lung adenocarcinoma) were higher than the corresponding control tissues. The gene discussed is DDX21; the disease is squamous cell lung carcinoma.