Brachiocephalic arteries are among the most commonly studied vessels in the analysis of atherosclerosis in murine models, and examination of those from TRAIL−/−ApoE−/− and ApoE−/− mice on 12 w HFD exhibited significant changes in cellular composition, particularly with the detection of chondrocyte-like cells and cartilaginous metaplasia. The gene discussed is APOE; the disease is atherosclerosis.