APOE and atherosclerosis: Due to the time-consuming and extremely difficult process to obtain Ppp2cαflox/flox CreLyz2 (cKO) mice on an ApoE−/− or LDLR−/− (low-density lipoprotein receptor knockout) background by crossbreeding cKO mice and ApoE−/− or LDLR−/− mice, we decided to apply in our study a novel, time-saving and effective animal model of atherosclerosis that has been reported and extensively used (27–30).