Wordwide use of the Serial Analysis of Gene Expression (SAGE) database has resulted in a vast amount of gene expression information. This immortal database couples quantitative transcript abundance data to specific genes and allows for the defining and delineation of new, active transcription units. Recent advances in SAGE technology have allowed the unambiguous, direct linking of SAGE tag data to complex, whole-genome data. With a vast, cancer-specific SAGE database in hand, researchers now have an opportunity for comprehensive, genome-wide transcriptome annotation relating to cancer.