To investigating that whether CRTAM owned a better diagnostic efficacy than classic RA related biomarkers, we carried a systematic comparison analysis between CTRAM and those genes, including MMP3, S100A8, S100A9, IL6, COMP, LAG3, and ENTPD1. As shown in Supplementary 9, we found that the expression level of CRTAM, MMP3, S100A8, S100A9, and ENTPD1 was higher in RA tissues in both training and testing cohorts. Here, S100A8 is linked to rheumatoid arthritis.