In addition,ALL1, a human homologue of Drosophila trithorax protein, whichcontains PHD zinc-finger domain, as well as other genes expressing proteins with PHDzinc-finger domains are also known to be frequently mutated in ALL and AML (Gu et al., 1992; Tkachuk et al., 1992; Nakamura et al., 1993; Parry et al., 1993; Chesi et al., 1998). The gene discussed is KMT2A; the disease is acute lymphoblastic leukemia.