The interaction between menin and MLL1 has been implicated in the development of acute leukemias driven by MLL1/KMT2A rearrangements (MLL1-r) (3, 4, 5, 6, 7), NPM1 mutations (NPM1-mut) (8, 9, 10, 11, 12), and NUP98 rearrangements (NUP98-r) (13, 14, 15). The gene discussed is MEN1; the disease is acute leukemia.