Titers of autoantibodies against the chimeric citrullinated fibrin/filaggrin peptides anti-CFFCP1, anti-CFFCP2, anti-CFFCP3, and against cyclic citrullinated peptide CCP2 in RA and control populations. Boxes represent interquartile range and median. Whiskers represent values outside the interquartile range. Single points represent outliers and extreme values. RA = rheumatoid arthritis; SLE = systemic lupus erythematosus; HCV = hepatitis C virus infection; PsA = psoriatic arthritis; BD = blood donor.