SARS-CoV-2, ACE2, and potential cardiovascular risk factors: assessing the vulnerability of COVID-19 infection. (A) Schematic diagram showing the risk of NO2 and nicotine in the modulation ACE2 expression, wherein levels of ACE2 and ratio of Ang II/Ang 1–7 determine the cardiovascular pathology. NO2 might increase, while nicotine might decrease the ACE2 levels, and this could alter the ratio of Ang II/Ang 1–7 in the heart triggering hypertension and risk of SARS-CoV-2 infection. Other potential factors that could potentially alter ACE2 expression include its genetic polymorphism, geographic localization, ethnicity, age, gender, and varied protein stability. (B) Graph (violin plot; image credit: Human Protein Atlas) shows the normalized protein expression of ACE2 levels in the blood plasma samples of the control males and females, where a relatively higher ACE2 expression can be seen in males than the females. (C) Graphs showing a lower ACE2 protein stability during death (on Hardy scale) and ischemia (calculated aa ischemic time) (image credit: Human Protein Atlas).