CCL2 and rheumatoid arthritis: Given the pivotal role of the CCR2 ligand CCL2 in leukocyte recruitment and inflammation within the RA synovium, we posited that CCR2 expression might be a critical determinant for the targeted homing of GMSC‐EVs to arthritic joints.​​ ​​This finding provided the molecular rationale for functionally interrogating the role of CCR2 in the subsequent experiments.​