Plasma concentrations of anti-nuclear antibody and anti-double-stranded DNA antibody in Murphy Roths Large (MRL)/lpr and BALB/c mice treated with interleukin (IL)-35 or phosphate-buffered saline (PBS) injection. Concentrations of plasma (a) anti-nuclear antibody (ANA) and (b) anti-ds-DNA antibodies are presented as bar charts with the arithmetic mean plus standard error of the mean (s.e.m.). *P < 0·05, ***P < 0·001, PBS versus IL-35 treatment; ††P < 0·01, †††P < 0·001, BALB/c control mice versus PBS-treated MRL/lpr mice; ‡P < 0·05, BALB/c control mice versus IL-35-treated MRL/lpr mice (n = 5 in each group).