APOE gene polymorphisms have been reported to be associated with susceptibility or severity of COVID-19 in British, Czech, Spanish, Finnish and Kurdish population (Kuo et al., 2020; Al-Jaf et al., 2021; Del Ser et al., 2021; Hubacek et al., 2021; Kurki et al., 2021). Here, APOE is linked to COVID-19.