CD80 and atherosclerosis: For instance, Ldlr-/- mice that lack B7-1/B7-2-T cell-costimulatory signals showed less atherosclerosis due to decreased T cell activation [17], whereas irradiated Ldlr-/- mice reconstituted with bone marrow cells lacking B7-1/B7-2 had increased plaque area through decreased Treg responses [18].