The unfolded protein response (UPR), a cellular stress response pathway, is broadly implicated in disease and resistance to therapy. The molecular mechanisms that drive stress-mediated chemoresistance are, however, only poorly understood. We have employed a multiomics approach to determine UPR-induced gene regulation, revealing the UPR regulon. We further observe metabolic rewiring upon stress and resistance to Methotrexate, a widely-employed therapeutic reagent. The precise molecular characterization of the pathway driving resistance might lead to novel concepts in cancer therapy.