APOE and atherosclerosis: Knockout of MERTK, a receptor tyrosine kinase responsible for recognition of apoptotic cells, in ApoE−/− mice results in a dramatic increase in necrosis and TUNEL staining; however, plaques volumes are not significantly increased [154], suggesting that IgM:receptor-mediated endocytosis may play a secondary role in terms of IgM in atherosclerosis.