RXRA and acute myeloid leukemia: This anti-AML effect was related, in part, to upregulation of vitamin D receptor (VDR) and retinoid X receptor (RXRα) levels compatible with increasing transactivation of the vitamin D response element (VDRE).What is more, silibinin activates the Nrf2/Antioxidant Response Element (Nrf2/ARE) signaling pathway, an upstream positive regulator of VDR and RXRα [17].