In conventional two-dimensional cultures of tumor cells, ER stress-inducing agents have been shown to activate the extrinsic apoptotic pathway through the PERK pathway-mediated induction of the CHOP transcription factor, leading to the upregulation of TRAILR2/DR5 expression [33], which induces the activation of caspase-8 at an intracellular DISC [33,43,57]. This evidence concerns the gene DDIT3 and neoplasm.