Individuals with chronic granulomatous disease (CGD), a genetic disorder caused by hypo- or amorphic mutations in genes encoding for Nox2 or its subunits, fail to produce sufficient amounts of ROS by Nox2 and in consequence suffer from increased susceptibility to infections [236] underscoring the importance of Nox2-derived ROS for antimicrobial immunity. Here, CYBB is linked to chronic granulomatous disease.