SAA1 and COVID-19: To distinguish high-risk (hospitalized) and low-risk (outpatient) COVID-19 cases, Lazari et al. [53] used a platform combining machine learning (ML) and MALDI-TOF-MS to analyze C18-fractionated plasma samples, identifying intact and truncated forms of serum amyloid proteins A-1 (SAA1) and A-2 (SAA2), known biomarkers for viral infections in the acute phase.