NETosis is a regulated process. (A) Representative image of a WT or PAD4^−/− neutrophil stimulated with calcium ionophore. WT neutrophils undergo histone hypercitrullination (H3Cit, green) and throw NETs, whereas PAD4^−/− neutrophils fail to citrullinate histones, decondense chromatin, or release NETs. Reproduced from Martinod et al.¹⁶  Scale bars, 10 μm. (B) In response to S aureus skin infection, neutrophils can secrete their nuclear contents (right) while retaining the ability to crawl and phagocytose, thus multitasking. Reproduced from Yipp et al with permission.¹⁹