PRTN3 and rheumatoid arthritis: This was substantiated in Cox regression analyses, where a positive SC ACPA test was found to be a significantly prognostic in the Karolinska risk RA cohort (HR 2.1 (95 % CI 1.4–3.1; p = 0.0002)), as well as in the TIRx cohort (HR 2.4 (95 % CI 1.3–4.6; p = 0.008)), both in univariable and adjusted analyses (Table 1).