To identify the potential regulators involved in VSMCs phenotypic switching and TAD progression, we use the public single-cell sequencing dataset (GSE155468) and found that Krüppel-like factor 15 (KLF15) transcripts are enriched in the VSMCs of healthy aortas but decreased in patients with aortic aneurysm. The gene discussed is KLF15; the disease is aortic aneurysm.