A few flavonoids were shown to suppress the activity of angiotensin-converting enzyme (ACE) (Guerrero et al. 2012; Nileeka Balasuriya and Vasantha Rupasinghe 2011), which not only plays an important role in cardiovascular diseases such as in hypertension, but may also represent a key determinant in viral infections, and pneumonia (Actis-Goretta et al. 2006). The gene discussed is ACE; the disease is viral infectious disease.