Hierarchical clustering for genes differentially expressed in HCC. For visual comparison, genes differentially expressed in HCC and normal liver were clustered by Treeview program. The expression pattern of these genes in HepG2 was also shown. The red color represents genes up-regulated, and the green color represents genes down-regulated. 1: normal liver, 2: normal liver from public database, 3: HCC SAGE, 4: HCC LongSAGE, 5: HepG2.