GSK2606414 is an orally available, selective protein kinase R-like ER kinase (PERK) inhibitor with an IC50 value of 0.4 nM. It can inhibit thapsigargin-induced PERK phosphorylation in lung carcinoma A549 cells and attenuates subcutaneous pancreatic human tumor xenograft growth in mice. Because PERK mediates the unfolded protein response pathway, which has roles in neurotoxicity and cancer, inhibition of PERK signaling has potential applications for the treatment of cancer and also cognitive degeneration.