To assess whether the SDF-1-CXCR4/CXCR7 axis was involved in the therapeutic potential of HP-MSCs, the cells were injected into the tail vein of I/R-AKI mice after pretreatment with a neutralizing anti-CXCR4 antibody, or an anti-CXCR7 antibody, or their respective isotype-matched antibodies. The gene discussed is CXCL12; the disease is acute kidney injury.