GFAP and COVID-19: Moreover, in a recent observational study conducted by Passoss et al., it has been demonstrated that the new coronavirus 2 is able to increase OS biomarkers’ serum levels, such as the glial fibrillary acidic protein (GFAP) and the receptor for advanced glycation end products (RAGE), whose increase is directly proportional to the level of neurological damage in patients affected by COVID-19 [23].