Secretome profiling of BT-474 and SKBR3 breast cancer cell lines also showed that exosomes were enriched in proteins associated with antigen processing/presentation, such as heat shock 70 kDa protein 5 (HSPA5), calreticulin (CALR), and proteasome activator complex subunit 2 (PSME2), and proteins associated with glycolysis/gluconeogenesis, such as triosephosphate isomerase 1 (TPI1) and phosphoglycerate mutase 1 (PGAM1) [97]. Here, CALR is linked to breast cancer.