Therefore, we generated IL‐33−/−ApoE−/− and ST2−/−ApoE−/− mice for a side‐by‐side analysis and in addition, treated ApoE−/− mice with a blocking anti‐ST2 or the isotype‐matched control antibody in order to investigate a potential protective effect of endogenous IL‐33 during atherosclerosis associated with a cholesterol‐rich diet. The gene discussed is APOE; the disease is atherosclerosis.