A mutant MLL1(Δ123-153)-ENL, which can bind Menin but not LEDGF, failed to cause leukemia initiation, while an artificial LEDGF(1–93)-MLL1(Δ1-40)-ENL (which cannot recruit Menin), in which the LEDGF(1–93) insert can directly tether MLL1-ENL to chromatin, can cause leukemia transformation [114]. The gene discussed is PSIP1; the disease is leukemia.