Besides the attenuation of angiotensin II activity [318], DPP4i may also prevent acute lung injury in response to different stressors [319–324] and has shown inhibitory effects on other coronaviruses, including the Middle East Respiratory Syndrome Coronavirus (MERS-CoV) [325–327], which could play protective role in the first and second stages of COVID-19 [328]. Here, AGT is linked to COVID-19.