ROS production is a component of trained immunity for some stimuli. ROS production is a component of trained immunity for some stimuli. The level of ROS production was significantly increased for monocytes trained with BCG and oxLDL; training with β-glucan decreased the level of ROS production (n = 6; *, P < 0.05 compared to the RPMI control; ***, P < 0.001 compared to the RPMI control; ns, not significant). Cells were trained for 24 h using β-glucan, BCG, or oxLDL, and normalized cell numbers were restimulated using zymosan. Luminol was added, and luminescence was measured for 1 h. RLU/s, relative light units per second. Siroon Bekkering et al. Clin. Vaccine Immunol. 2016; doi:10.1128/CVI.00349-16