Microglia express NADPH oxidases (NOX) and in many neurodegenerative diseases (NDDs) microglia activation and the ensuing oxidant production through NOX2, together with proinflammatory response including cytokine secretion, play major roles in disease pathogenesis (Block et al., 2007; Tejera and Heneka, 2019). Here, FMO5 is linked to neurodegenerative disease.