Apoe−/−Ige−/− and Apoe−/−Ige+/+ were produced by breeding the Apoe−/− mice (#002052, C57BL/6J, The Jackson Laboratory, Bar Harbor, ME, USA) and Ige−/− mice18 (link). Nhe1+/– mice (#003012, C57BL/6J, The Jackson Laboratory) were bred with Fcer1a−/− mice5 (link) to produce the Fcer1a−/−Nhe1+/– mice. Six-week-old Apoe−/−Ige−/− (C57BL/6J, N=10) and Apoe−/−Ige+/+ (C57BL/6J, N=10) mice consumed a high cholesterol (1.25%) atherogenic diet (#D12108c, Research Diets Inc. New Brunswick, NJ) to induce atherosclerosis. Results from this study are limited to males. It is possible that IgE activity in atherosclerosis may differ in females according to the ATVB council statement19 (link). Their body weights and food intake were measured weekly. After 12 weeks, mice were euthanized by CO2, followed by cardiac puncture blood and peritoneal macrophage collection, heart and aortic arch and root tissue harvest. Liver and adipose tissues, including epididymal adipose tissue, subcutaneous adipose tissue, and brown adipose tissue were isolated and weighed. All animal procedures conformed to the Guide for the Care and Use of Laboratory Animals published by the US National Institutes of Health and was approved by the Brigham and Women’s Hospital Standing Committee on Animals (protocol #2016N000442).