Factor H is a protein that plays a crucial role in the immune system, specifically in regulating the complement system. This system helps the body fight infections and clear damaged cells. Factor H helps prevent the complement from attacking the body’s own cells by binding to them and inhibiting the activation of the complement pathway. Deficiencies or abnormalities in Factor H can lead to various health issues, including Atypical Hemolytic Uremic Syndrome (aHUS) and Age-Related Macular Degeneration (AMD). These conditions can cause serious complications, highlighting the importance of Factor H in maintaining a balanced immune response and protecting the body from damage.