When levels in RA patients were the focus, initially ACPA-positive patients showed a nonsignificant median increase from 74 AU/mL (IQR 25 to 252) to 80 AU/mL (IQR 24 to 229), whereas in initially IgM-RF-positive RA patients, median IgM-RF levels decreased (P < 0.001) from 94 IU/mL (IQR 51 to 188) to 81 IU/mL (IQR 41 to 178). This evidence concerns the gene PRTN3 and rheumatoid arthritis.