Review Article

Pathogenetic, Clinical, and Prognostic Features of Adult t(4;11)(q21;q23)/MLL-AF4 Positive B-Cell Acute Lymphoblastic Leukemia

Table 1

The most common fusion partner genes of MLL: locations and functions.

Partner geneLocationFunction

AF44q21 NuclearLeads to RNApol-II activation and to transcriptional elongation
AF99p22 NuclearIn association with ENL, DOT1L, and AF4, activator of RNApol-II kinase p-TEFb
ENL19p13.3 NuclearElongation factor. In association with AF9, DOT1L and AF4 activator of RNApol-II kinase p-TEFb
AF1010p12 NuclearTranscriptional factor
ELL19p13.1 NuclearElongation factor interacts with a nuclear protein related to AF4
AF66q27 CytoplasmaticMulti-domain protein involved in signaling and organization of cell junctions during embryogenesis
AF1P1p32 CytoplasmaticPart of the EGFR pathway, involved in receptor-mediated endocytosis of EGF

p-TEFb: positive transcription elongation factor b. p-TEFb phosphorylates serine residues of the carboxy-terminal domain of RNApol-II; RNApol-II: RNA polymerase II; CTD: carboxy-terminal domain kinase; DOT1L: DOT1-like, histone H3 methyltransferase; EGFR: epidermal growth factor receptor; EGF: epidermal growth factor.