Although AAV9-Fat-1 treatment may facilitate the reduction of lipid levels in LDLR−/− hamsters fed a CD and induce the formation of anti-atherosclerotic plasma lipoprotein profiles, thus serving as a strategy for the reduction of cardiovascular events in patients with FH, we cannot ignore its lipid-lowering effect in CD-fed WT hamsters with normal lipid levels, implying that the application of Fat-1 expression to treat human metabolic diseases should be carefully considered to avoid any adverse effects. Here, FAT1 is linked to metabolic disease.