Re: Ferdinando Fusco, Roberta d'Emmanuele di Villa Bianca, Emma Mitidieri, et al. Sildenafil Effect on the Human Bladder Involves the L-cysteine/Hydrogen Sulfide Pathway: A Novel Mechanism of Action of Phosphodiesterase Type 5 Inhibitors. Eur Urol 2012;62:1174-80