Enables superoxide-generating NADPH oxidase activator activity. Involved in several processes, including reactive oxygen species biosynthetic process; regulation of respiratory burst involved in inflammatory response; and respiratory burst. Located in several cellular components, including Golgi apparatus; neuronal cell body; and rough endoplasmic reticulum. Part of NADPH oxidase complex. Used to study rheumatoid arthritis. Human ortholog(s) of this gene implicated in Williams-Beuren syndrome; autosomal recessive chronic granulomatous disease cytochrome b-positive type I; and chronic granulomatous disease. Orthologous to several human genes including NCF1 (neutrophil cytosolic factor 1). [provided by Alliance of Genome Resources, Apr 2022]