The simultaneous activation of neutrophils by chemokines and integrins is required for NET formation. In vitro NET formation was induced by incubating isolated neutrophils with TRAP-stimulated platelets or unstimulated platelets as control or incubation with different stimulating agents. NET formation was visualized by immunofluorescence staining. Exemplary images of NET formation by isolated neutrophil incubated with (A) unstimulated platelets and (B) TRAP-stimulated platelets. (C-F) NET structures in the supernatant were quantified by MPO-DNA-ELISA (n = 4). *P < .05.