APOE and familial hypercholesterolemia: The opposing effects of hypercholesterolemia on wound healing in C57BL/6 LDLr−/− mice and C57BL/6 apo E−/− mice may be related to distinct effects of pro-atherogenic lipoproteins on skin fibroblasts and granulation tissue formation, to differences of HDL cholesterol levels in these models, and to direct effects of apo E on wound healing.