APOE and atherosclerosis: Examining atherosclerotic lesion development in ApoE−/− mice on either a C57BL/6 or BALB/c genetic background, which display opposing TH responses revealed that ApoE−/− mice on a C57BL/6 genetic background, which have predominantly TH1 responses, develop significantly more atherosclerosis than ApoE−/− mice on a BALB/c genetic background, which have predominantly TH2 responses [164].