Gene expression determinants of clinical outcome

Purpose of review Gene expression profiling of human cancers has produced a large amount of information that could aid physicians in making decisions related to the treatment of their patients. A number of recent studies have identified collections of genes and corresponding expression levels that correlate with the physical appearance and clinical behavior of all common human neoplasms. Recent findings This article will discuss emerging trends of study design and approaches to gene expression signature identification. Recently discovered gene expression signatures that correlate with cellular morphology, resistance to chemotherapy, and overall clinical course of disease are discussed. Summary The prospective evaluation of the predictive value of a number of gene signatures is now appropriate. Newly discovered gene expression signatures that correlate with disease clinical course should be independently evaluated. The timely reporting of both positive and negative results from such validation attempts will be crucial to the advancement of molecular pathology.