IL10 and rheumatoid arthritis: In a PTOA model, i.a. injection of retrovirus-mediated genetically modified rabbit synoviocytes into rabbit knee joints containing human IL-10 and IL-1ra showed that gene delivery of both genes combined resulted in a stronger chondroprotective effect by blocking cartilage degradation and decreasing the loss of proteoglycans [217], while, in another study, IL-10 gene therapy of transduced human RA synovial cells or monocytic THP1 cells under a CXCL10 responsive promoter (CXCL10p-IL10 vector) reduced the production of inflammatory cytokines in response to stimulation with LPS [218].