The recently demonstrated efficacy of anti-Lcn2 antibody therapy in slowing mammary tumor growth and metastasis in mice [2] together with the potential use of small molecules and chemical chaperones to inhibit Grp78 and UPR [27,37], identifies the ER stress-Lipocalin 2 axis as a novel target for synergistic therapeutic intervention in several cancers, including prostate cancer. This evidence concerns the gene HSPA5 and breast cancer.