Recently, it has been postulated that EndMT may play a role in the development of PAH, we performed WB experiments to explore the role of EndMT in the development of PAH, as shown in Fig. 5A, B, Collagen I and collagen III, the main components of the extracellular matrix (ECM), were notably increased in the MCT group and MCT + AAV1-NC group, whereas these alterations were significantly inhibited by the knockdown of eIF3a. Here, EIF3A is linked to pulmonary arterial hypertension.