Phosphodiesterase-5 (PDE5) inhibitors have shown a beneficial effect in a variety of clinical conditions, such as benign prostate hyperplasia, pulmonary arterial hypertension, female sexual arousal disorder, overactive bladder, and incontinence, Raynaud's disease, heart failure and stroke among others (Sandner et al., 2007). The gene discussed is PDE5A; the disease is benign prostatic hyperplasia.