Sildenafil, better known as Viagra, has revolutionized the treatment of erectile dysfunction. The mechanismIn the past, research on the effectiveness of sildenafil in cancer patients had given conflicting results. Under the effect of sildenafil, cholesterol actually remains trapped inside the cells. And as research shows, tumors are extremely sensitive to this mechanism, particularly in the phases in which tumor cells attempt to break away from the primary mass to give rise to metastases. Neoplastic cells also possess strong adaptive capabilities and could develop alternative metabolic pathways to circumvent the absence of cholesterol.