HMOX1 and COVID-19: SARS-CoV-2, the virus that causes COVID-19, has a tremendous ability to bind porphyrins with even stronger affinity than ACE-2 receptors, resulting in the upregulation of free heme, an oxidant, and severe reactive oxygen species (ROS) formation, and decreased levels of heme oxygenase-1 enzymes (HO-1) [4].