The RNA of low-grade selenoproteins degrades rapidly during selenium deficiency, while the RNA of high-grade selenoprotein remains stable, resulting in increased selenium reuse and faster resynthesis of selenoproteins (Banning et al., 2008b).In the GPX family with Sec as the active center, GPX2 has the highest rating, followed by GPX4, GPX3 and GPX1 (Banning et al., 2008b). The gene discussed is SELENOS; the disease is selenium deficiency.