ERAP2 and hypertensive disorder: Based on these considerations, we speculate that the genetic variants of ERAP1 and ERAP2 linked to hypertension and autoimmune diseases [33,34,35,36,37], such as ERAP1 rs30187, could enhance the stimulation of the ACE/Ang II/AT1R axis (Figure 4b), and thus help to explain the variety of courses, as well as the differential pattern of gender and ethnicity of COVID-19.