C3 and asthma: It has been reported that mice lacking Toll-like receptor 2 (TLR2) or complement component 3 and those with defective IL-1 receptor/TLR signaling stimulated with Staphylococcus aureus do not release NETs from their neutrophils.[64] NETs can also be induced by stimulation with pro-inflammatory factors, such as IL-33,[67] CXCL8,[68] IL-17,[69] and C3a/C5a,[70] which are important inducers of NET formation and are associated with asthma pathophysiology.