To test the possible promotion of atherosclerosis by macrophage-expressed Rcan1, we reconstituted the BM of 2-month old lethally irradiated Apoe−/− mice with BM-derived cells from Apoe−/−Rcan1−/− or Apoe−/− mice, thereby generating Apoe−/− mice with either Apoe−/−Rcan1−/− macrophages (Rcan1−/− → Apoe−/−) or Apoe−/−Rcan1+/+ macrophages (Rcan1+/+ → Apoe−/−). The gene discussed is APOE; the disease is atherosclerosis.