Activating K-ras mutations occur in 80-95% of pancreatic cancers. The purpose of this study was to conduct an open, panoramic survey of gene expression, using K-ras status as the axis over which to sub-classify pancreatic cancers. Differential display was used to contrast mRNA purified from exponentially growing PANC-1 and Capan-2 cells (mutated K-ras) with Hs766T and BxPC-3 cells (wild-type). Differences were confirmed by Northern analysis. Twenty-five transcripts were differentially expressed by a factor of two or more. Four transcripts were over-expressed and twelve were under-expressed in the mutants relative to the wild-types. The transcripts most strikingly over-expressed by the mutant cell lines were MARCKS, DKFZp547C244, and RPLP2. The transcripts over-expressed by the wild-types were CEACAM6, cDNA AK026924, and myosin light chain-6. Profiling of gene expression with respect to K-ras mutation status may lead to new insights into pancreatic cancer pathogenesis, as well as to the identification of novel therapeutic targets.