Thoracic aortic aneurysm (TAA) significantly endangers the lives of individuals with Marfan syndrome (MFS), yet the intricacies of their biomechanical origins remain elusive. Our investigation delves into the pivotal role of hemodynamic disturbance in the pathogenesis of TAA, with a particular emphasis on the mechanistic contributions of the mammalian target of rapamycin (mTOR) signaling cascade. We uncovered that activation of the mTOR complex 1 (mTORC1) within smooth muscle cells, instigated by the oscillatory wall shear stress (OSS) that stems from disturbed flow (DF), is a catalyst for TAA progression. This revelation was corroborated through both an MFS mouse model (