However, PDX models have supported the approval of drugs for other cancers, including AG-221 and SH1573 for IDH2 R140Q-mutant acute myeloid leukemia (AML) and elacestrant for ER+ breast cancer.75, 76, 77, 78 Mutations in IDH1 and IDH2 genes are common in several cancers, including AML, where they disrupt blood cell differentiation and promote leukemogenesis.79 This evidence concerns the gene IDH2 and breast cancer.