The gene encoding the Mixed-Lineage Leukemia (MLL) proteins is located on chromosome 11q23. Chromosomal translocations involving band 11q23 result in rogue activator proteins that are associated with approximately 10% of patients with acute lymphoblastic leukemia (ALL) and 5% of patients with acute myeloid leukemia (AML). Most patients affected are less than 1 year of age. The gene encoding MLLT6, also known as mixed-lineage leukemia translocated to 6 or AF17, is located on chromosome 17q12 and encodes a 1093 amino acid protein that is thought to be involved in the translocations on chromosome 11q23. Localized to the nucleus, MLLT6 contains a leucine-zipper dimerization motif located 3-prime of the fusion point and a cysteine-rich domain at the C-terminus. MLLT6 is thought to play a role in ALL by repressing the activity of the truncated ALL1 protein.