In order to try and resolve these issues, we measured the triangular relationships between CFH-CFHR3-CFHR1 genotypes, plasma concentrations of CFHR1 and CFH plus FHL-1 (hereafter referred to as ‘CFH’) and AMD susceptibility, using both cross-sectional population cohort (n = 1004) and AMD case–control series (1256 cases, 1020 controls) (see Supplementary Material, Table S1 and Fig. S1). Here, CFHR1 is linked to age-related macular degeneration.