Immunofluorescence (IF) staining of the mature SMC marker SMMHC and the SMC contractile marker αSMA demonstrated a significant decrease of SMC density in aortic vascular media and phenotypic switches in abdominal aortic aneurysm indicated by SMC morphology alteration (Figure 2C). The gene discussed is MYH11; the disease is abdominal aortic aneurysm.