TLR4 and neoplasm: To determinate whether activation of TLR4 expressed on tumor cells influences the immune-modulatory properties of released exosomes, CFSE-labelled PBMCs, isolated from healthy donors, were incubated for 24 hours with scalar doses (from 5 × 106 to 5 × 109) of exosomes and then stimulated with anti-CD3/-CD28.