DNA array/microarray technology is becoming one of the most productive methods for characterizing physiological and pathological processes and is being used to elucidate the complex interdependence present in biological systems that cannot be carried out by classic methodologies. This technology is particularly well suited to the study of cancer and has already permitted the identification of subtypes of different tumors with clinically relevant subtypes. As for other neoplasms, an improved understanding of pancreas cancer genetics is the only means to provide new markers for earlier diagnosis and to identify potential targets for therapeutic intervention. Transcriptional profiling using DNA arrays has the potential to satisfy these requirements. To date, only a few reports have emerged regarding the analysis of common pancreatic cancer by these techniques. Initial expression profiles using macroarrays have been generated and expression profiles of the cancer cell and the desmoplastic reactions on cDNA arrays have been performed using material obtained by fine needle aspiration. More recently, microarrays have been used to identify genes abnormally expressed in chronic pancreatitis with respect to pancreatic cancer and normal pancreas. Gene expression profiles will also be invaluable for the study of other less common pancreatic tumor types such as intraductal, ampullary, serous microcystic, acinar, and endocrine tumors.