Exosomes are secreted or released by essentially all cell types, certainly most immune and non-immune cells including macrophage, dendritic cells (DCs), B cells, T cells such as CD8+ cytotoxic T-lymphocytes (CTLs) and CD4+ T helper (TH) cells, platelets, mastocytes, fibroblasts, epithelial cells, as well as tumor cells. This evidence concerns the gene CD4 and neoplasm.