Abstract: The invention relates generally to the field of cancer diagnosis, prognosis, treatment and prevention. More particularly, the present invention relates to methods of diagnosing, treating and preventing lung cancer. In particular, aspects of the invention are directed to methods of diagnosing, treating and preventing small cell lung cancers. Methods of using a nucleic acid and/or a protein, which are differentially expressed in tumor cells, and antibodies immunospecific for the protein, to treat, diagnose and/or prevent said cancers, are provided for by the present invention.