Cannabinoid receptor TRPV1 is expressed by human OA chondrocytes and human OA and RA synovial fibroblasts.29,32 TRPV1 acts as a receptor for the endogenous cannabinoid AEA and has also been shown to bind the phytocannabinoid: cannabidiol (CBD).17,18 CBD has anti-inflammatory and hypoalgesic effects in a rat model of acute inflammation, through TRPV1 activation.47,48. Here, TRPV1 is linked to rheumatoid arthritis.