RAS^mut is enriched in t-AML and is associated with poor prognosis. (A) t-AML was more prevalent in RAS^mut than RAS^wt t-MN. (B) t-AML was especially more prevalent in the presence of KMT2A-r. (C) Substitutions at amino acid position 13 (G13D/C) were highly enriched in t-AML. In contrast, mutations at position 12 (G12D/V/C) were more frequently associated with t-MDS. (D) RAS^mut was associated with survival comparable to TP53-mutated t-MN, (E) t-MDS, and (F) t-AML. (G) Multivariable Cox proportional hazard analysis demonstrated that RAS^mut was associated with poor survival independent of allo-SCT, t-MN phenotype, and CKs. (H) NRAS^mut was associated with significantly poorer OS than KRAS^mut t-AML. Allo-SCT, allogeneic stem cell transplant; OS, overall survival.