Substrate stiffness activates YAP and TAZ,6 and, in certain models, such as pulmonary hypertension, this may elicit a vicious cycle in which YAP and TAZ, via various downstream mechanisms, further promote matrix stiffness.43, 44, 45 Our present results are in keeping with this overall paradigm because we find passive mechanical properties of the colon to be robustly altered. Here, YAP1 is linked to pulmonary arterial hypertension.