Maintenance of healthy arteries requires a balance between injuries to the arterial wall and processes of intrinsic arterial repair. Such repair requires the availability of progenitor cells that are local to the wall itself. Progenitor cells from distant reservoirs like the bone marrow may also contribute to repair. Arterial repair seems to degrade over a lifetime, particularly with risk factors such as smoking and diabetes. Hence, a potential preventive/therapeutic strategy for atherosclerosis could be transfusion of competent bone marrow cells (BMCs) to restore effective repair in the face of arterial injury and depleted endogenous repair reservoirs. The challenge with this strategy has been the reliable collection and/or generation of BMCs that support arterial repair. In this study, we describe a set of experiments to elucidate a method of culturing BMCs that robustly retards atherosclerosis development in apolipoprotein E knockout mice. Identifying such a method would represent an important step in developing cell-based treatments for patients with proclivity for developing atherosclerosis.