However, WHO-HAEM5 eliminates the 20% blast requirement for AML by defining genetic abnormalities (except AML with BCR::ABL1 fusion, AML with CEBPA mutation, AML-MR, and AML with other defined genetic alterations).[4] In ICC, blasts must reach 10% or more, except in AML with BCR::ABL1 fusion, AML-TP53, AML-MRGM, AML-MRCA, and AML, NOS.[5] Some AML subtypes require ≥ 10% blast cells in ICC but ≥ 20% in WHO-HAEM5, such as AML with CEBPA mutations, AML with RUNX1T3(CBFA2T3)::GLIS2, AML with KAT6A::CREBBP, AML with FUS::ERG, AML with MNX1::ETV6, and AML with NPM1::MLF1. The gene discussed is FUS; the disease is intrahepatic cholangiocarcinoma.