In one case, a patient diagnosed with left parotid myoepithelial carcinoma and possible metastatic nodules in the lung received two doses of the Moderna mRNA-1273 COVID-19 vaccine, to which they experienced a severe adverse reaction that resolved within two weeks, and over the next 9 months, showed a 73% reduction in tumor burden associated with a phenotypic shift in the tumor immune microenvironment from a pro-tumorigenic (characterized by M2 macrophages) to a pro-inflammatory anti-tumor phenotype enriched in CD8+ T cells [91]. The gene discussed is CD8A; the disease is neoplasm.