Isofistularin-3 (Iso-3, derived from Aplysina aerophoba) sensitized cells to TRAIL in RAJI and U-937 cancer cell lines (pre-treatment at 15 μM) [93]; this was associated with apoptosis and ER stress (elevated GRP78 protein as well as CHOP RNA levels) [93]. Here, HSPA5 is linked to cancer.