TDO2 and aortic stenosis: Specifically, based on RNA sequencing results, the genes APCDD1L, CDH6, COL10A1, IBSP, KRT14, PLEKHS1, PRSS35, and TDO2 were significantly upregulated in both AS and AI valves compared to NC valves, while ALDH1L1, EPHB1, GPX3, HIF3A, and KCNT1 were significantly downregulated in both AS and AI valves compared to NC valves.