Gui et al. (2014) reported that many members of the ECS inhibit synovial inflammation, hyperplasia, and cartilage destruction in RA. In particular, activation of CB2 may relieve RA by inhibiting the production of autoantibodies, proinflammatory cytokines, and matrix metalloproteinases (MMPs), as well as bone erosion, T cells mediated immune response, and the proliferation of FLSs (Gui et al., 2014). This evidence concerns the gene CNR2 and rheumatoid arthritis.