Another selected seed node from the proteomics layer was Superoxide Dismutase 2 (SOD2), an essential antioxidant enzyme that protects cells from superoxide radical anions which are known to be significantly under-expressed in the plasma (Žarković et al., 2022), and in the lung cells of severely infected COVID-19 patients (Zarkovic et al., 2022). Here, SOD2 is linked to COVID-19.