CXCL12 and atherosclerosis: Given the CXCL12/CXCR4 axis to be angiogenic in general (Ara et al., 2005; Unoki et al., 2010), but also in tumor development (Domanska et al., 2013) and potentially in atherosclerotic lesions (Di Stefano et al., 2009), and angiogenesis being considered to increase plaque vulnerability, the question still remains if this reflects an important unfavorable role of CXCR4 in atherosclerosis.