ABCA1 and atherosclerosis: Interestingly, it has been reported that PPARγ, which increases the levels of ABCA1/G1 and LDLR (important molecules for cholesterol efflux and absorption, which are key regulatory processes in atherosclerosis), regulates the phenotypic polarization switch of M1/M2 macrophages and enhances the polarization of M2 macrophages [45,46].