NOX4 and bronchiolitis obliterans syndrome: NOX4 expression was significantly increased in the BO-group (Control vs. BO; 100 ± 17 vs. 148 ± 39%, P < 0.01 vs. Control), and the increase was suppressed by Cap (BO vs. BO + Cap; 148 ± 39 vs. 102 ± 16%, P < 0.05 vs. BO) (Fig. 5C).