Panobinostat enhanced the acetylation of GRP78 (glucose-regulated protein 78) and increased endoplasmic reticulum stress via upregulation of p-eIF2α, CHOP and ATF4, and elevation of BIK, BIM, Bax and BAK expression, acceleration of the caspase-7 activity and UPR in breast cancer cells (69). Here, BAK1 is linked to breast cancer.