PCSK9 serum levels of controls were 0.17 (0.06–0.36) μg/mL, of patients with moderate COVID-19 were 0.37 (0.11–0.72) μg/mL, and of patients with severe COVID-19 were 0.41 (0.20–1.16) μg/mL when patients with liver cirrhosis were excluded. Here, PCSK9 is linked to COVID-19.