JAK2 and atherosclerosis: To assess whether the defect in cholesterol efflux plays a causal role in the accelerated atherosclerosis in M-Jak2 mice, we treated BMDM from M-Jak2 WT and KO mice with an LXR agonist TO901317 which is known to enhance cholesterol efflux through transcriptional upregulation of the cholesterol transporters ABCA1 and ABCG120.