Our results showed that, in the early stage (day 7) of Ang II‐induced aneurysm‐related AIP, apoptotic VSMCs predominately induced the proliferation of neighboring VSMCs, whereas in the middle (day 14) and late (day 21) stages, apoptotic VSMCs mainly promote the adjacent VSMC apoptosis, indicating an unbalance between apoptosis and proliferation of VSMCs, which in turn leads to the loss of VSMCs and aneurysm. The gene discussed is AIP; the disease is aneurysm.