In this scenario, this study aims to investigate the location and expression of the AT1, Mas, and MrgD receptors in the lung tissue and of Angiotensin I (Ang I), Ang II, Angiotensin A (Ang A), Ang-(1-7) and ALA peptides in the plasma of patients with and without IPF. The gene discussed is ANG; the disease is idiopathic pulmonary fibrosis.