CD8A and colon carcinoma: The treatment of B16 melanoma and CT-26 colon carcinoma cells with Hsp70-containing EVs causes full-scale antitumor effect, reduction of tumor growth and prolongation of life-span that may be linked to a strong activation of innate immunity, elevation of anti-cancer cytokine levels and increase in CD8-positive cells and reduction of M2 type pro-tumor macrophages.