LEP and synovitis: Exogenous leptin abdominal cavity injection in ob/ob mice can lead to different levels of oxidative stress and increased inflammation-related gene expression,[51] indicating that leptin might change the course of the arthritis by regulating immune response in the whole body or the articular cavity.[17] Synovitis is a very important process in early OA and there are now experiments targeting synovial angiogenesis early treatment to reduce symptoms of OA.