TGFB1 and COVID-19: In particular, 5 metabolites (arginine, creatine, 3-hydroxyoctanoyl carnitine, 3,5-tetradecadiencarnitine, and 1-stearoyl-2-hydroxy-sn-glycero-3-PE) distinguished between severe and non-severe COVID-19, while 10 proteins resulted differential (HSPA8, IGFALS, LGALS3BP, PDIA3, PDLIM1, PFN1, PTGDS, RAP1B, SERPINA10, TGFB1).