In particular, activated MDSCs reduce the number of CD4+ and CD8+ lymphocytes, as well as NK cells, and down-modulate their cytotoxic capabilities as a result of the interaction between exosomal tumor HSP72 (heat shock protein 27), myeloid-derived TLR-2 (Toll-like receptor 2) and MyD88 (myeloid differentiation primary response protein 88) [73]. Here, CD4 is linked to neoplasm.