FLRT2 and COVID-19: Concomitantly, increased proteins were related to COVID-19 inflammation [Tnf (58)], injury [Matn2 (56)] and severity [Tnfsf12 (57); Vegfd (63)], angiogenesis and endothelial cell growth [Vegfd (63); Flrt2, fibronectin leucine-rich transmembrane protein 2 (64)], neuronal activity [Sez6L2 (51), Gfra1 (49), Igsf3 (53), Tnr (52), and contactins (Cntn1 and Cntn4) (65)], thrombosis [cdh6, cadherin 6 (66)], and cell growth and survival [Riox2, ribosomal oxygenase 2 (67)].