SELENOP and hyperinsulinemic hypoglycemia, familial, 4: Studies of recent months show a close relationship between Se, Selenoprotein P (Sepp1) deficiency, oxidative stress level and COVID-19 disease incidence, severity and prognosis (Cheng and Prabhu 2019; Moghaddam et al. 2020; Saito 2020; Zhang et al. 2020).