The WHO 5th divides AML into 2 main groups: AML, with defining genetic abnormalities, and AML, defined by differentiation. Furthermore, the revised classification has eliminated the 20% blast requirement for AML harboring defining genetic abnormalities (except for AML with BCR: ABL1 and AML with CEBPA mutation).

In line with other WHO series, the 5thWHO-Hem has also generated a category of Genetic tumor syndromes to include genetic syndromes associated with increased risk for hematolymphoid tumors. These genetic syndromes include Fanconi anemia, Ataxia telangiectasia, Bloom syndrome, and RASopathies.

The Revised European-American Classification of Lymphoid Neoplasms (REAL) classification is based on the principle that each type of lymphoma is a distinct disease defined by morphology, immunophenotypic and genetic features, clinical presentation, and course.