IL-10, a crucial immunoregulatory cytokine secreted by various lymphoid and myeloid cells, including Th2, CD4, CD8 T cells, NK cells, macrophages, and dendritic cells, can be produced by tumor cells themselves, acting as a cytokine synthesis inhibitory factor (CSIF) leading to immunosuppression [22]. The gene discussed is CD8A; the disease is neoplasm.