Menin is a multifunctional scaffold protein that serves as a scaffold between TFs and chromatin modifiers at genes related to hematopoietic proliferation and differentiation, such as HOX and MEIS1, providing a mechanistic explanation for the efficacy of Menin inhibitors in MLL-rearranged and NPM1-mutated leukemia. The gene discussed is KMT2A; the disease is leukemia.