VEGF and lung-homing of endothelial progenitor cells (EPCs) driven by stromal cell derived factor-1 (SDF-1) binding CXCR4 receptor are crucial to bronchial vascularity in asthma (Imaoka et al., 2011; Janssens et al., 2018; Laddha and Kulkarni, 2019). Here, CXCL12 is linked to asthma.