Factors that promote tumorigenesis encompass a wide array of proteins that include transcription factors, signal transduction molecules, negative regulators of tumor suppressors, transmembrane receptors and enzymes involved in a variety of processes. Identifying these factors remains one of the most pertinent issues in cancer research, as they can be used as both diagnostic markers and therapeutic targets. The ability to characterize tumors based on molecular markers will enable one to easily assess tumor severity, select a method of treatment and ultimately improve patient outcome. While the treatment of primary tumors has improved by leaps and bounds over the past decade, metastases continue to plague both patients and the research community. Along these lines, markers that predict metastatic potential will help to both limit secondary tumor growths and improve patient outcome.