Interestingly, in these studies of global, hematopoietic and monocyte/macrophage-specific TREM2 KO mice, atherosclerosis decreased in both the apoE KO and low-density lipoprotein receptor (LDLR) KO, classic mouse models of atherosclerosis (45, 52, 53). This evidence concerns the gene TREM2 and atherosclerosis.