Representative western blotting images of salivary CK13 and Cit-CK13 in 11 patients with RA (age [years]: median 65.0, 95% confidence interval: 56.9–73.9; two males, nine females) and ten healthy individuals (age [years]: median 30.5, 95% confidence interval: 29.4–31.2; four males, six females) are shown in Figs 4 and 5. The gene discussed is KRT13; the disease is rheumatoid arthritis.