Inhibition of Rac1 has been shown to prevent metastasis of bladder cancer.233 In non-cancerous pathology, Rac1 contributes to pulmonary hypertension via its role in NO-mediated smooth muscle relaxation.234 Disruption of Rac1 macrophage regulation has been shown to increase disease stability in atherosclerosis as well,235 highlighting its role in development of the disease. This evidence concerns the gene RAC1 and pulmonary arterial hypertension.