Nine individual proteins were significantly higher in COVID-19+ patients adjusting for age, sex, and BMI with an FDR less than 0.1 (Figure 3D): ISG15, polypeptide N-acetylgalactosaminyltransferase 1 (GALNT1), isocitrate dehydrogenase (NAD+) 3 non-catalytic subunit γ (IDH3G), glycine cleavage system protein H (GCSH), Ras-related protein 18 (RAB18), nuclear transport factor 2–like export factor 1 (NXT1), protein phosphatase 2 regulatory subunit B’’ alpha (PPP2R3A), USO1 vesicle transport factor (USO1), and retinoic acid early transcript 1L (RAET1L) (Figure 3E). Here, RAB18 is linked to COVID-19.