An overarching principle in this context is the requirement to consider “post cytotoxic therapy” and “associated with germline [gene] variant” as disease attributes that should be added as qualifiers to relevant myeloid disease types whose criteria are fulfilled as defined elsewhere in the classification, e.g. AML with KMT2A rearrangement post cytotoxic therapy or MDS with low blasts associated with germline RUNX1 variant. This evidence concerns the gene RUNX1 and acute myeloid leukemia.