Furthermore, we speculate that APTO‐253 may also target other diseases associated with NOTCH3 mutations or overexpression, including solid tumors, such as head and neck squamous cell carcinoma, ovarian cancer, and lung adenocarcinoma [11], as well as cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) [28] and pulmonary arterial hypertension [20]. Here, NOTCH3 is linked to pulmonary arterial hypertension.