(−)-Agelasine D (derived from the Agelas sponge) induced a potent cytotoxic response across a series of liver cancer cell lines (with a GI50 of 9.9 μM), which coincided with the induction of ER stress (elevated levels of p-ERK and ATF4 proteins) in Hep3B cells [91]. Here, ATF4 is linked to liver cancer.