Figure 1.

Prevalence of antibodies against peptides derived from endogenous retrovirus (HERV)‐K envelope (env) protein. Seventy rheumatoid arthritis (RA) patients and 71 healthy controls were screened for immunoglobulin (Ig)G antibodies by indirect enzyme‐linked immunosorbent assay (ELISA) against HERV‐K env_19–37, (a), HERV‐K env_109–126 (b), HERV‐K env_164–186 (c) and HERV‐K env_205–226 (d) peptides. Scatterplots present median values with interquartile range. Area under receiver‐operating characteristic (ROC) curve (AUC) as well as significant P‐values are displayed.