CXCL12 and precursor B-cell acute lymphoblastic leukemia: Juarez J et al. found that CXCL12 synergized with interleukin (IL) -7 or IL-3 was associated with enhanced phosphorylation of the mitogen-activated protein kinases (MAPK), extracellular signal-related kinase 1/2 (ERK1/2) and p38, and AKT, implicating these pathways in the proliferation of B-ALL [45].