CXCL8 and acute promyelocytic leukemia: Previous studies have indicated that ATRA-induced granulocytic differentiation in APL cells is associated with (a) increased production of pro-inflammatory cytokines, such as interleukin (IL)-1, IL-6, IL-8, monocyte chemotactic protein-1, tumor necrosis factor-α, and others [20,21,22,23]; (b) an excess release of cathepsin G to enhance capillary permeability and damage [24]; and (c) the upregulation of leukocyte integrins to promote their adherence to capillary endothelium and organ infiltration [25].