Additionally, HDL or ApoA-I levels were significantly lower in severe, critically ill and mortality groups compared to patients with mild COVID-19 (Wang et al., 2020b; Huang C. et al., 2020; Ouyang et al., 2020; Xie et al., 2020; Zhang Q. et al., 2020; Hilser et al., 2021; Li J. et al., 2021; Turgay Yıldırım and Kaya, 2021). The gene discussed is APOA1; the disease is COVID-19.