At the molecular level, angiotensin II (Ang II), a critical neurohormonal ligand constituent of the renin-angiotensin system (RAS), plays a vital role in cardiac fibrosis by promoting CF proliferation and increasing the production of proinflammatory cytokines and ECM proteins through the activation of Ang II type 1 receptor (AT1R) (12, 13). The gene discussed is AGT; the disease is cystic fibrosis.