Moreover, the levels of specific peripheral biomarkers that are routinely used in clinical practice for AD diagnosis—such as total tau protein in association with IL-6, Neurofilament Light Chain (NFL) and Glial Fibrillary Acidic Protein (GFAP)—are elevated in the CSF and serum of COVID-19 patients [197,198]. The gene discussed is IL6; the disease is COVID-19.