Retinoids can reverse various premalignant lesions as well as prevent some second primary tumors. The effects of retinoids are regulated by retinoic acid receptors (RAR) and retinoid X receptors, which act as ligand-activated transcription factors. Ligand-dependent transcriptional activation of RARs is a multistep process that ends with the formation of a multimeric co-activator complex on regulated promoters (1,2). Loss of RAR-beta expression and the accumulation of p53 and Ki67 proteins may help in the early identification of esophageal cancer in high-risk populations (3).
