REN and sarcoidosis: The renin–angiotensin system (RAS); angiotensin-converting enzyme (ACE), which is present in high levels in the serum of patients with sarcoidosis; and ACE2, which is an essential and major receptor for the SARS-CoV-2 to enter the cell, may also play a key role in the link between COVID-19 and sarcoidosis (11, 12).