Illustration of extravasation and directional migration of MSCs in different conditions.

(a) Morphology of a normal MSC. (b) An MSC under SDF-1α gradient. (c) An MSC exposed to Y-27632, a Rho-ROCK inhibitor. (d) An MSC exposed to AMD3100, a CXCR4 antagonist. (e) MSC exposed to NSC23766, a Rac inhibitor. (f) Migration of MSCs due to the chemokine effect of SDF-1α. Blue color represents the number of stem cells migrating in response to the homing factor.