IFNG and COVID-19: This study compares metabolic (SIRT1, AMPKA, HIF1A, and GLUT1) and inflammatory (NFKB1, NFKB1A, IFNG, and SOCS1) gene expression, and flow cytometry-based assessment of functional markers in NK cells from severe COVID-19 patients (n=15) and the control group (n=10), and their association with clinical outcomes.