In contrast, the APOE4 allele (in Cx3cr1-deficient mice) was found to be protective through reduced ApoE expression and subretinal MP accumulation, compared with APOE3. These results highlight the importance of differential behaviour of APOE isoforms in retinal inflammation, as well as potentially distinct pathogenic roles played by systemic versus local APOE in AMD pathogenesis when taken in the context of the work by Malek et al. above (Figure 1b). The gene discussed is APOE; the disease is age-related macular degeneration.