FPR1 and cystic fibrosis: However, there was a negative correlation between phagocytosis and the production of ROS by CF neutrophils in patients with CF stimulated with PMA (r = −0.499, p < 0.05), fMLP/LPS (r = −0.476, p < 0.05), and OpZym (r= −0.536, p < 0.05) (Figure 4B).