It was also shown that hypoxic glioma-derived exosomes promote M2-like macrophage polarization by enhancing autophagy induction [188] and MCF-7 breast cancer cells with undetectable MMP2 protein acquired expression of MMP2 and corresponding gelatinase activity after stimulation with exosomes derived from mesenchymal stromal stem cells [189]. Here, MMP2 is linked to central nervous system cancer.