To determine the on-target effects of allosteric SMURF1 inhibitors on the global proteome in a relevant disease-specific cellular context, PASMCs from patients with PAH were pre-treated with BMP4 under hypoxic conditions and exposed to the SMURF1 inhibitor or a vehicle (Figures S5B and S5C). Here, BMP4 is linked to pulmonary arterial hypertension.