RUNX1 and leukemia: Recent WHO classifications of myeloid neoplasia have progressively emphasised the importance of AML defining genetic abnormalities such as RUNX1::RUNX1T1 and co-occurring molecular alterations, highlighted by removal of the requirement of over 20% blasts in marrow to define leukaemia when AML-defining genetic abnormalities are present (Khoury et al., 2022).