The overall results indicated a significant association between the PDGF/PDGFR system expression and RA (OR = 5.25, 95% CI: 3.00-9.18, p < 00001), RA patients in Asian countries (OR = 4.13, 95% CI = 2.04-8.39, p < 0.0001) and in Western countries (OR = 9.18, 95% CI = 2.04-8.39, p = 0.03), and only PDGF expression in RA patients (OR = 5.28, 95% CI = 2.73-10.21, p < 0.00001). The gene discussed is PDGFRB; the disease is rheumatoid arthritis.