Taming the dragon: genomic biomarkers to individualize the treatment of cancer.

The gradual shift from cytotoxic drugs to highly selective, targeted therapeutic agents for cancer requires a parallel effort to characterize cancers at the molecular level to guide the choice of therapy for the individual patient. Here we review the genomic technologies that can be used to develop these drug response indicators, or biomarkers. We also discuss hurdles in their development and the implementation of biomarkers in clinical practice.