IL-26–20KK elicited a higher Ab seroreactivity accounting for 39% (n = 55) among RA patients and 7% (n = 10) in HCs (p < 0.0001, Fig. 1A), while Abs against IL-256–70 were detected in 23% (n = 32) of RA subjects and 8% (n = 13) of HCs (p = 0.0031, Fig. 1B). Here, IL26 is linked to rheumatoid arthritis.