HSPA1A and neoplasm: Previous studies have only explored free circulating Hsp70 [17, 18], whereas we have developed the Hsp70-exo sandwich Enzyme-linked immunosorbent assay (ELISA) which is able to measure not only free Hsp70 derived from dying cells, but also eHsp70 that is actively released from living tumor cells in lipid microvesicles [19–22].