Sildenafil or tadalafil, an inhibitor of phosphodiesterase 5, widely used for erectile dysfunction and pulmonary hypertension treatment [130], was also shown to be a promising strategy to prevent Tau toxicity: by activating cGMP (cyclic guanosine monophosphate)-dependent protein kinase, the stimulated proteasome activity reduced the level of Tau protein and decreased the associated morphological abnormalities in the zebrafish human TauA152T model [204]. The gene discussed is MAPT; the disease is pulmonary arterial hypertension.