The future of diagnostic gene-expression microarrays: bridging the gap between bench and bedside

During the last two decades, an increasing number of microarray studies have identified gene-expression profiles that link disease characteristics to patient outcome. However, despite improvements in technology and the clinical relevance of the identified profiles, only a handful of microarray tests are currently available for clinical use. So why have microarrays, regardless of the great application and success within a research setting, not yet been embraced for routine diagnostic use? Besides the strengths of microarray diagnostics, this perspective will outline the important challenges that need to be considered for successful translation of a gene profile into a routine diagnostic test. Finally, some new microarray technologies will be reviewed and an outlook for the future of diagnostic microarrays will be presented.