We have addressed the phenotype composition and functionality of 2 widely used in vitro macrophage models in atherosclerosis research, i.e. BMDMs and PEMs, and compared them to aorta derived macrophages from ApoE−/− mice with initial and established disease to elucidate whether any of the two constitute a more appropriate model for plaque associated macrophages. The gene discussed is APOE; the disease is atherosclerosis.