PDGFRB and rheumatoid arthritis: As a result, the association between PDGF/PDGFR system expression in RA patients located in Western countries has 9.18 odds of significant association than that in the nonarthritic group as shown in Figure 3(d) of the meta-analysis (OR = 9.18, 95% CI = 2.04-8.39, p = 0.03).