STAT4 and COVID-19: Considering that STAT4 participates in interferon signalling hyperstimulated during SARS-CoV-2 infection and the implications of peroxisome proliferator-activated receptors (PPARs) in COVID-19 hyperinflammation (Lee et al. 2020, Hasankhani et al. 2023), these results further corroborate the biological relevance of APNet’s insights regarding the broader involvement of ACAA1 and other highly predictive plasma proteins in severe COVID-19 pathobiology (Fig. 5H and I).