Author: Nat Pernick, M.D. (see Authors page)

Revised: 24 September 2015, last major update November 2013

Copyright: (c) 2003-2015,, Inc.

PubMed Search: MLL[title]
Cite this page: MLL / ALL1. website. Accessed August 19th, 2018.
Definition / general
  • Gene at 11q23 called MLL (mixed lineage leukemia), ALL1, HRX and Htrx (from Drosophila trithorax protein)
  • Note: ALL1 may also signify Allergen 1 gene in Cryptococcus (Mol Microbiol 2013;88:713)
  • A histone H3 methyltransferase (GeneCards)
  • Epigenetic transcriptional regulator that controls proliferative expansion of immature hematopoietic progenitors in part by methylating histone 3 on lysine 4
  • Required for normal development, but also mutated in subset of aggressive human leukemias
  • Epigenetics: study of heritable changes in gene expression or chromosome stability that don't alter the underlying DNA sequence; epigenetic changes are established through DNA methylation, non-coding RNAs and covalent modification of specific residues on histone proteins (Cancers (Basel) 2012;4:904)
  • Genetic alterations found in pediatric (particularly infant) and 5-10% of adult de novo and therapy-related acute lymphoblastic leukemias or acute myeloblastic leukemia (Haematologica 2013;98:825)
Clinical features
MLL tumors:
  • Rarely associated with intravascular diffuse large B cell lymphoma (Arch Pathol Lab Med 2009;133:1477)