SLC7A11 and COVID-19: Therefore, we next measured the expression of transporters, GLUT1 (SLC2A1) and xCT (SLC7A11), that are key transporters of glucose/mannose and antiporter of glutamate respectively, in PBMCs of HC (n = 19), HC-CoV-2 Ab+ (n = 9), and COVID-19 patients: mild (n = 21) and severe (n = 11) using flow cytometry.