Regarding the impact of PBA on UPR in U87 carrying wtp53, the finding that the downregulation of BIP occurred only at a higher dose in these cells could be explained by the absence of mutp53 that has been reported to help cancer cells to survive and adapt to conditions of chronic stress, due to intrinsic and extrinsic insults [7,21,25]. This evidence concerns the gene HSPA5 and cancer.