XBP1 and cancer: Based on the above findings that fucoidan can modulate ER stress response in the cancer cells, we next examined whether fucoidan differentially regulates IRE-1\XBP-1 s, a cascade defining cell survival response via up-regulating the expression of chaperones for ER folding capacity [31], and the PERK\P-eIF2α\CHOP pro-apoptotic cascade [17].