Figure 1 Patterns of mPR3 expression before and after priming with TNFα. Neutrophils were isolated and stained for mPR3 expression before (A–D) and after priming with TNFα (E–H). (A, E) Representative overlay of an individual with monomodal expression of mPR3 on neutrophils before priming (A), and (E) a bimodal expression of mPR3 observed after priming. (B, F) An individual in whom before (B) and after priming (F) bimodal mPR3 expression is observed. (C, G) An individual in whom all neutrophils before (C) and after priming (G) show apparent mPR3 expression (>90% mPR3⁺ cells). (D, H) An individual in whom all neutrophils show a lack of mPR3 expression before (D) and after (H) priming (>90% mPR3^– cells). The grey peak represents isotype control; the black line represents mPR3 expression, and CD35 expression is represented by the dashed line.