VEGFA and rheumatoid arthritis: To evaluate whether the in vitro effect of adiponectin on the expression of VEGF, MMP-1, and MMP-13 is associated with the expression of these genes in the joint fluid of RA patients, we measured the levels of adiponectin, VEGF, MMP-1, and MMP-13 in the joint fluid of RA or OA patients (Figure 3).