Described herein are antibodies and antibody fragments capable of treating or preventing cancers associated with the over-expression and/or up-regulation of DKK1. Also disclosed are methods of treating or preventing cancer using the antibody and methods and kits utilized to diagnosing cancer. The herein described products and methods find utility in the context of a variety of cancers, such as pancreatic cancer, gastric cancer, liver cancer, prostate cancer, breast cancer, cervical cancer, bile duct cancer, lung cancer and esophageal cancer.
