RARA and acute promyelocytic leukemia: Tamibarotene, a synthetic retinoid acid receptor (RAR)α/β-selective agonist developed to overcome all-trans retinoic acid (ATRA) resistance, induces RAR/retinoid X receptor (RXR)-mediated differentiation and tolerability in relapsed/refractory acute promyelocytic leukemia (APL) [44], but has not yet been studied in melanoma.