RARS1 and acute myeloid leukemia: This idea is also consistent with the clinical findings that regular ATRA has some detectable but not striking results against AML [78] or solid tumors, but second and third generations of much more stable and potent retinoid derivatives show little efficacy [85], likely because they potently target RARs or RXRs, but no longer bind to Pin1 [28, 86].