IL18R1 and rheumatoid arthritis: RA further differed from SLE by the upregulated expression of TLR2 (Pcorr = 0.02; Figure 1(a), Tables 2(a) and S3A) and from SSc by the upregulation of TLR3, IL1RAP, and IL18R1 genes (Pcorr < 0.007; Figure 1(b), Tables 2(b) and S3B).