CXCL12 and diabetic kidney disease: When SDF-1-CXCR4-related maladaptive control occurred, podocyte progenitors of the Bowman’s capsule would proliferate in crescentic glomerulonephritis [23], hypoxia-induced upregulation of CXCR4 in nephrosclerosis was observed [24], and there was insufficient podocyte regeneration in diabetic nephropathy [25].