Consistent with this notion, CCR2 and CCL21/CCR7 have been reported to play a role in the recruitment of bone marrow-derived fibroblast precursors into the kidney and the development of renal fibrosis (Sakai et al., 2006; Reich et al., 2013; Xia et al., 2013a). This evidence concerns the gene CCR2 and renal fibrosis.