CXCR4 and cancer: In response to inflammation, MSCs express a variety of chemokine and cytokine receptors (CXCR1, CXCR2, CCR1, CCR2, etc.)that can drive MSCs to the inflammatory sites by migrating toward inflammation and thus control inflammation locally.98 Some key receptor/chemokine pairs include CXCR4/SDF‐1, CX3CR‐1/fractalkine, CCR7/CCL21, as well as RANTES and MDC with their receptors (CCR2, CCR3, and CCR4).99 Overexpressing homing receptors such as CCR1 and CXCR4 could improve MSC migratory behavior toward injured and inflamed sites and the cancer microenvironment.