CDKN2A and atherosclerosis: However, atherosclerosis is associated with defective efferocytosis,26 and both VSMC and macrophage apoptosis in atherosclerosis can be associated with inflammation, which can promote atherogenesis.27,28 The number of TUNEL+ apoptotic cells in aortic root plaques was increased in GCV-treated p16→p16 mice (which express p16-3MR in both vessel wall and bone marrow-derived cells), and in GCV-treated p16→ApoE mice (which express p16-3MR in vessel wall-derived cells), with similar appearances of the TUNEL+ cellular debris in the plaque cores (Figure 3A and C).