In order to develop effective vaccine products against human cancer, we are interested in identifying genes over-expressed in tumor cells. Through a combination of cDNA library subtraction and microarray technology, we identified seventeen genes preferentially expressed in lung squamous cell carcinoma, including four novel genes. To date, expression profiles of these genes were confirmed by Northern and/or real-time analysis, and several genes were also found to be expressed in head and neck squamous tumors. Thus, these combined methods represent a high throughput approach for identifying tumor specific genes. Furthermore, the report of characterization on these genes will allow them to be exploited for their diagnostic, prognostic, and therapeutic potentials including immunotherapy and antibody based anticancer therapy.