In the complement factor H family, there are five CFHR proteins have been identified, which are divided into two major groups, Group I and Group II, based on their conserved domains. Complement factor H-related protein 1 (CFHR1), a member of Group I CFHR proteins, is a plasma protein circulating in two glycosylated forms at the concentration of 70 to 100 μg/mL. Learn more: Complement Factor H Related Protein 1