Moreover, it can activate extrinsic pathways of apoptosis by activating the pro-apoptotic proteins, which lead to upregulation of C/EBP homologous protein (CHOP), glucose-regulated protein 78 (GRP78), inositol requiring enzyme-1(IRE1a), and JNK as observed in murine and human breast cancer cells [107]. Here, ERN1 is linked to breast cancer.