Progress in techniques and computer processing over the last few years have led to the development of new methods of molecular biology. These new methods allow rapid data processing, often allowing data to be shared via networks. An example of this new technology is the transcriptome analysis via a microarray chip. This chip allows analysis of a very large number of RNA messenger transcripts that can be used for diagnostic or prognostic purposes. The first applications in lung cancer have been aimed to distinguish pulmonary adenocarcinoma from other adenocarcinomas. Another approach is to use these chips as a diagnostic tool to identify genes with expressions specific for non-small-cell lung cancer. The early results have been promising and encouraging for future developments, particularly in the domain of applied therapeutics.