ACE2 and COVID-19: Susceptibility of specific organs to COVID-19 has provoked research towards the disease mechanisms [5], which resulted in identification of spike glycoprotein (S protein), one of the main structural components of SARS-CoV-2, which facilitates binding of the envelope viruses to host cells by forming homotrimers protruding on the viral surface, which attracts angiotensin-converting enzyme 2 (ACE2) [6].