IL‐10 has been demonstrated to drive lung fibrosis when overexpressed, and this process is dependent on CCL2 signaling20 and is elevated in serum following knee surgery.17 CCL2 levels correlate positively with patient's pain levels following primary TKA, suggesting a role for CCL2 in pain pathogenesis, and recruitment of monocytes by knee fibroblasts in vitro is dependent on CCL2 signaling.14 CCL3 and CCL4 are elevated immediately following knee surgery17 and CCL13 is a key mediator of immune cell recruitment in chronic inflammation. Here, CCL2 is linked to pulmonary fibrosis.