Cholesterol biosynthesis is inhibited by the expression of SESN-1 and PCSK9, and is regulated by transcription factor and NRLP3 inflammasome.24,43 A recent study has confirmed that cholesterol biosynthesis is increased by the activity of SREBP-2; but at the same time, SESN-1 and PCSK9 are expressed and inhibitory results were demonstrated.24 In severe COVID-19 patients, the biosynthesis of cholesterol such as intracellular HDL needs to be promoted and then subsequent homeostasis takes place as a result of the increase in SREBP-2 activity. Here, PCSK9 is linked to COVID-19.