SARS-CoV-2 is known to activate mast cells in affected patients, along with other immune cells including monocytes/macrophages, neutrophils, T cells, killer cells, and resident tissue epithelial and endothelial cells. These various groups cells have been thought to induce the "cytokine storm syndrome" that is experienced by COVID-19 patients. However, since mast cells are well-expressed throughout the body (including the CNS) and are involved in certain neuroinflammatory diseases, it is hypothesized that their activation by SARS-CoV-2 upregulates certain neuroinflammatory responses, which may result in some of the other symptoms observed in COVID-19 patients, including ischemic stroke.