Furthermore, the reduction of total lung capacity and the consequent hyperventilation, also due to the growing uterus, can cause one to inhale more air within the same period of time with more exposure to SARS-CoV- infection [6, 7], while also affecting the maternal immune system (an increase in maternal serum levels of toll-like receptors TLR-1 and TLR-7, and the increase of angiotensin-converting enzyme 2 [ACE-2]), which can decrease the efficacy of viral clearance [8, 9] and increase the risk of several diseases. The gene discussed is ACE2; the disease is severe acute respiratory syndrome.