OLFM4 and necrotizing vasculitis: In addition to LDNs and PMN-MDSCs, other subsets of neutrophils have been identified in humans during cancer, anti-neutrophil cytoplasmic antibody-associated systemic vasculitis, and bacterial infections with Staphylococcus aureus and E. coli, including N1/N2 neutrophils, C177 expressing neutrophils, and Olfactomedin-4 expressing neutrophils (Rarok et al., 2002; Fridlender et al., 2009; Hu et al., 2009; Liu et al., 2012; Liu et al., 2013; Grieshaber-Bouyer and Nigrovic, 2019; Filep and Ariel, 2020).