RARB and acute promyelocytic leukemia: Cases with NPM1 fusions or indels outside the C terminus38 clustered with canonical NPM1 mutations, and we assigned them to the NPM1 category (Extended Data Fig. 4a); similarly, we assigned a RAR family fusion, TBL1XR1::RARB, to the acute promyelocytic leukemia category based on expression similarities with PML::RARA cases.