F2 and COVID-19: Notably, in hospitalized patients the complex expression profile including HERV-W, N-SARS, IL-6, IL-10, and TNF-α positively correlates with fibrinogen, while the component loaded on TLR-3, TLR-7, IL-17RA, and HERV-K correlates negatively with prothrombin (%), D-dimer, and CD4 T cells (%) and positively with fibrinogen and CD19 B cells (%), suggesting the involvement of HERVs in the pathogenesis of COVID-19.