This study found that proteins of the extracellular matrix (PPIA and MMP-9), astrocytes (S100β and GFAP), and neurons (NfL) were increased in both COVID-19 patients with neurological deficits and those in the intensive care unit (ICU), compared to healthy controls, with the levels of these proteins higher in ICU patients, with the exception of MMP-9, which showed the opposite change. The gene discussed is NEFL; the disease is COVID-19.