Summary and analyses of SAGE libraries. (A) Summary of SAGE tags generated from normal cartilage and the SRC tumors. The total number of SAGE tags and the number of unique tags are listed for each SAGE library. (B) Heat map displaying the differentially expressed genes between RNC and SRC tumor tissues. Rat normal (articular) cartilage has a unique expression profile when compared to the expression profiles of the SRC tumors. The changes in gene expression may represent critical differences between normal cartilage cells and chondrosarcoma, and they may also represent changes important for the development and progression of chondrosarcoma. Heat map displays the differentially expressed genes that were expressed at a level of at least 25 tags in one library. For complete gene list see Additional file 2. Color bar illustrates relative gene expression levels. (C) The list of differentially expressed genes was analyzed with the pathway-mapping program Ingenuity. The top five functional pathways and their corresponding p-values are displayed in table (see “Methods” for description of p-value).