TMEM97 and COVID-19: COVID-19 infects cells with low ACE-2 receptor concentration [low ACE-2R] and high [ACE-2R] with worse outcomes occurring in high [ACE-2R] cells because COVID-19 has a high affinity for the porphyrin substrate on hemoprotein within the cell, which causes a decrease in functional intracellular hemoprotein levels (Figure 2).