ACE2 and COVID-19: Furthermore, ACE2 is also found in the membrane of cells in the liver,[6] intestines, kidney, testis, gallbladder, and heart,[5] which accounts for why COVID-19 is a systemic disease and can cause shock, acute cardiac injury, multiple organ failure and eventual death.[7] Therefore, it is of urgency to study the mechanism of how COVID-19 interacts with other diseases.