HNRNPDL and rheumatoid arthritis: To verify the results from protein macroarray screening, hnRNP-DLmir was expressed in E. coli BL21(DE3)pLysS, purified and tested for reactivity in ELISA as native (DL) and citrullinated protein version (cit-DL), using 1010 sera obtained from Risk-RA cohort (n = 71), from early RA cohorts (LURA n = 106; EIRA n = 404), from an established RA cohort (predict n = 127), control cohorts of other autoimmune diseases (n = 216) and from healthy controls (n = 86).