On the other hand, IFNα serum levels were increased in RA patients compared with HC (20.25±47.61 vs. 1.76±3.08 pg/ml, p = 0.001), and positively correlated with all endothelial progenitor populations in patients (EPC: r = 0.294, p<0.001; mEPC r = 0.265, p<0.001, pre-EPC r = 0.367, p<0.001) but not in controls. The gene discussed is IFNA1; the disease is rheumatoid arthritis.