SAA4 and rheumatoid arthritis: Notable proteins in the shared alteration (early and established RA conditions) included SAA4, CCL18, TNFRSF10A, ST6GAL1, CRTAC1, TNFRSF11A, FGF23, IL6, TF, ANGPTL3, TNC, PRSS8, SERPINA5, CST3, TIMD4, CTSL1, C2, VSIG2, EFEMP1 and SORT1 (Supplementary Figure 1).