Electroacupuncture in a rat model of knee osteoarthritis led to elevated levels of synovial norepinephrine through β2‐AR, which suppressed excessive IL‐6 production in synovial macrophages by targeting the CXCL1‐CXCR2 pathway, ultimately relieving osteoarthritis [47]. This evidence concerns the gene CXCR2 and osteoarthritis.