Beyond macrophages, discussed previously, the most well-studied immunecell population in response to tumor EV communication is the T lymphocyte.Cytotoxic CD8+ T lymphocytes together with CD4+ T helper 1cells are the key regulators of antitumor immunity (note that regulatoryCD4+ T cells known as Tregs are a potent immunosuppressive subsetof CD4+ T cells also found in the TME) (93). The gene discussed is CD4; the disease is neoplasm.