ROC curves of confirmed proteins showed that the levels of IL-2 (AUC=0.830), IL-5 (AUC=0.820), IL-11 (AUC=1.000), IL-17 (AUC=0.850), TNF-β (AUC=0.820), CTLA-4 (AUC=0.770), IL-8 (AUC=0.740), PD-L2 (AUC=0.830), B7-2 (AUC=0.740), which indicated that these proteins can be used as potential molecular markers for the diagnosis of poor SPP in RA. Here, IL2 is linked to rheumatoid arthritis.