CRLF2 and acute lymphoblastic leukemia: Among recently reported genomic abnormalities in ALL, a subset of BCP-ALL patients has been characterized by over-expression of the Cytokine Receptor-like Factor 2 (CRLF2) gene, associated with either an intra-chromosomal deletion causing the P2RY8-CRLF2 fusion or the IGH@-CRLF2 translocation [14, 15].