It frequently manifested in female patients and in patients with splenomegaly, M4 subtype, c‐Kit gene mutation, and rearrangements of RUNX1‐RUNX1T1 or CBFB‐MYH11, commonly referred to as core binding factor AML (CBF‐AML). The gene discussed is CEBPZ; the disease is acute myeloid leukemia.