In a mouse model for diet‐induced obesity, HFD caused disruption of tight and adherens junction proteins in coronary arterial endothelium, which was accompanied by the activation of endothelial Nlrp3 inflammasome, enhanced expression of HMGB1 and T cell adhesion and infiltration in the coronary arterial walls. The gene discussed is NLRP3; the disease is obesity due to melanocortin 4 receptor deficiency.