In contrast, normal individuals who are infected by SARS-CoV-2, may face less complications than elder and comorbid patients specifically with pneumonia, ARDS, kidney injury etc. [45] and it might be due to the change of HIF level and as a consequence imbalance regulation of ACE/ACE2 ratio due to the increase in hypoxia, ACE and decrease in ACE2 imparts a major role in hypoxic pulmonary hypertension (HPH) (Figure 1:5,A) [34]. This evidence concerns the gene ACE2 and pneumonia.