LDLR and focal segmental glomerulosclerosis: Investigating the underlying mechanisms of glomerular foam cell formation in FSGS, using NEP25 (podocyte-selective injury), LDLR−/− (hypercholesterolemia) and NEP25/LDLR−/− mice, neither hypercholesterolemia nor podocyte injury alone was sufficient to induce macrophage/foam cell infiltration to glomeruli.