ARRB2 and lung adenocarcinoma: Gene expression profiling interactive analysis data (GEPIA, http://gepia.cancer-pku.cn/detail.php?gene=ARRB2) showed that ARRB2 expression was decreased in lung tumor (Supplementary Fig. S1A, tumor vs. normal) and significantly down-regulated in both lung adenocarcinoma (LUAD) and lung squamous cell carcinoma (LUSC) (Supplementary Fig. S1B, *p < 0.05).