Overall, 80% of COVID19 patients had increased levels of either diffuse or dense clusters (microglial nodes) of microglia, 68% displayed detectable CD8+ T cell infiltration into the parenchyma and 36%–44% had the most severe phenotype, which was associated with some degree of axonal damage (but no signs of necrotic cell death) in the medulla [117]. The gene discussed is CD8A; the disease is COVID-19.