Downregulation of IL-9 by anti-IL-9 mAb and LncRNA CASC11 induced the opposite effect (22, 23) and research by Brown and colleagues suggests that IL-9 reducing smooth muscle 22α and may promote phenotype transformation of SMC through the STAT3 pathway, which may exacerbate vascular dysfunction and lead to the formation of AAA (24). The gene discussed is IL9; the disease is triple-A syndrome.