HDAC6 and cancer: Moreover, by inhibiting the release of exosomes containing GRP78 from cancer cells, HDAC6 inhibition also inhibits angiogenesis as GRP78 is involved in blood vessel formation in growing tumors through the activation of HIF-1α and VEGF/VEGFR, as well as the PI3K/AKT, ERK, and FAK signaling pathways [92].