CD274 and Encephalopathy: MDSCs are known to expand in a diverse range of inflammatory conditions.39 As a population of heterogeneous immature monocytes, MDSCs are important in suppressing T cells by expressing high levels of inhibitory receptor (e.g., PDL-1).24 Hence, we propose that for COVID-19, these cells dampen the host immune response and potentiate COVID-19-associated encephalopathy pathogenesis.