FMO5 and aspergillosis: Neutrophil cytosolic factors (NCFs) are part of the group of proteins that form the enzyme complex called NADPH oxidase, and mutation in any of the key genes NCF1, NCF2, and NCF4 leads to impaired fungal eradication (as in aspergillosis) due to non-functional NADPH oxidase (Panday et al., 2015; Giardino et al., 2017; Dinauer, 2019; Wu et al., 2019).