CALR and glioblastoma: Numerous proteins released by exosomes derived from GBM are linked to the formation of invadopodia and the consequent ability of GBM to invade, including integrin β1 (ITGB1), Annexin A1 (ANXA1), actin-related protein 3 (ACTR3), calreticulin (CALR), and programmed cell death 6-interacting protein (PDCD6IP), as well as others [70].