The present application provides the amino acid and nucleic acid sequences of heavy and light chain complementarity determining regions of a cancer specific antibody directed to an epitope of variant Nuclear Factor Kappa-B inhibitor beta (NFKBIB). In addition, the application provides cancer specific antibodies and immunoconjugates comprising the cancer specific antibody attached to a toxin or a label, and methods of uses thereof. The application also relates to diagnostic methods and kits using the cancer specific antibodies herein. Further, the application provides novel cancer-associated epitopes and antigens of variant NFKBIB, and uses thereof.
