Functional genomics and expression profiling: be there or be square.

The manuscript by Hong and colleagues in this issue of the American Journal of Respiratory Cell and Molecular Biology (1) profiling the downstream genes activated by expression of the tumor suppressor gene, PTEN , represents one of the first papers published in this journal that makes use of complementary DNA (cDNA) microarrays. cDNA microarray analysis is one of the most important new areas that has emerged from the ongoing revolution in functional genomics. This paper provides some background material and highlights the importance and promise of this new technology for lung researchers.