IGFBP2 and rheumatoid arthritis: The results showed that the expression of IGFBP2 was slightly higher in patients with SS (n = 16, P > 0.05) and higher in patients with RA (n = 16, P < 0.05) than that in HCs (n = 18), whereas the level of IGFBP2 in active LN patients (n = 17) was significantly higher than that in RA and SS patients (P < 0.01) (Fig. 2A).