CFHR1 is a secreted protein belonging to the complement factor H protein family.The human complement factor H protein family consists of the complement and immune regulators factor H, the factor H-like protein 1(FHL-1) and five factor H-related proteins (CFHR-1 to -5). Members of the H-related protein family are exclusively composed of individually folded protein domains, termed short consensus repeats (SCRs) or complement control modules. CFHR1 binds to Pseudomonas aeruginosa elongation factor Tuf together with plasminogen, which is proteolytically activated. CFHR1 might be involved in complement regulation. It can associate with lipoproteins and may play a role in lipid metabolism.