Book excerpt: This volume presents state-of-the-art information on each of the arms of the unfolded protein response (UPR), how their activation/repression are regulated, integrated, and coordinated, how UPR components affect cancer cell biology and responsiveness to therapeutic interventions, and how UPR components/activities offer potentially novel targets for drug discovery, repurposing, and development. The volume will provide the most recent information on the signaling and regulation of the UPR, explore examples of how the UPR and/or specific components contribute to cancer biology, and identify and explore specific examples of potently new actionable targets for drug discovery and development from within the UPR and its regulation. Unique to the volume will be a specific focus on the UPR and its role in cancer biology, as well as a discussion of the role of the UPR in drug responses and resistance in cancer.