The homing functions were owing to the fact that MSCs expressed many chemotaxis receptors such as CCR1, CCR2, CCR4, CCR5, CCR9, CXCR1, and CXCR5; the CCR2 and CCR4 were major migration helpers of MSCs in colitis, and CXCR4 combined with SDF-1 can promote MSCs migration [74]. This evidence concerns the gene CCR4 and colitis.