In the September 25th online edition of Stem Cells, C. P. Jones et al. from the Imperial College (London, UK) reported their study results on the involvement of bone marrow-derived endolthelial progenitors cells (EPCs) in remodeling inflamed lungs in an allergic airways mouse model. The investigators found an angiogenic response concomitant with recruitment of EPCs at day 24 during acute inflammation of the lungs. EPCs isolated and propagated in vitro expressed CD31, vWF and VEGFR2 and they were negative for CD45 and CD14. The experimental results revealed an increase in the levels of pro-angiogenic factors CXCR2 ligands (CXCL1 and CXCL2) and VEGF-A. However, the researchers found that VEGF-A alone was ineffective in recruiting EPCs to the lung after allergen exposure. Additionally, CXCR2 blockade reduced trafficking of EPCs to the lungs with a decrease in the numbers of peribronchial blood vessels in the inflamed lungs (post-allergen administration). The authors concluded from their animal study that "CXCR2 is critical for both EPC recruitment and the angiogenic response in (their) model of allergic inflammation in the airways"