CFHR4 and age-related macular degeneration: In two recent studies evaluating the systemic levels of all five FHR proteins (Cipriani et al., 2021; Lores-Motta et al., 2021), common AMD genetic variants and haplotypes at the CFH locus strongly associated with FHR-1, FHR-2, FHR-3, FHR-4 and FHR-5 protein concentrations, whereas the association with FH concentrations was limited (Supplementary Fig. 2).