The invention provides a method for inhibiting proliferation of cancer cells, as well as methods for detecting and treating various cancers, including cancer of the brain, lung, breast, prostate and colon. The method comprises contacting a cancer cell with a molecule that disrupts the biological activity of a GDOX molecule. In one embodiment, the molecule is an antibody directed against a GDOX peptide. In other embodiments, the molecule is an antisense nucleotide directed against a GDOX nucleic acid molecule, or a vaccine comprising a GDOX peptide or a polynucleotide encoding a GDOX peptide. The invention additionally provides methods for detecting and treating cancer using GDOX-related molecules.