NCF4 (Neutrophil Cytosolic Factor 4): NCF4 is a component of the NADPH oxidase complex that plays a key role in the body’s immune defense. It helps regulate the assembly and activation of this complex, enabling the production of reactive oxygen species (ROS) during the oxidative burst in phagocytes. This process is essential for destroying engulfed pathogens, and mutations in NCF4 can impair immunity, leading to greater susceptibility to infections.