Second, compared to the gain-of-function role of RARα in ESCC tumors, the formation of esophageal carcinogenesis is attributed to the loss of RARβ expressions, but the induction of RARβ expressions in EC cells enhances cell apoptosis via reducing cyclooxygenase-2 expression [13]. The gene discussed is RARA; the disease is esophageal squamous cell carcinoma.