Breakage of the KMT2A gene, commonly known as the MLL gene and located at 11q23, leads to a poor prognosis AML with relapse rates of 35% following allo-HCT in adult patients (93), while AML with an isolated mutation of NPM1 has an incidence of post-allo-HCT relapse of 12-22% when transplant is performed in first remission (94). The gene discussed is KMT2A; the disease is acute myeloid leukemia.