In another study, a peptide aptamer that binds to the extracellular domain of the Hsp70 membrane and targets Hsp70-expressing exosomes in BC patients was used; this is because the Hsp70 molecules exposed on the exosome membrane are able to interact with the Toll-like receptor 2 on the surface of myeloid-derived suppressive cells, thereby activating the latter and protecting tumor cells from immune recognition [168]. Here, HSPA1A is linked to breast cancer.