Chemically induced rat liver cancer proceeds through multiple, distinct initiation-promotion-progression stages and mutation of the suppressor p53 gene has been found in relatively early preneo-plastic lesions in the rat liver.19 In the present study, gene network analysis using the characteristic genes in Group 1 revealed that almost all the annotated genes were formed one network related with p53 gene (Fig. 4(A)). This evidence concerns the gene TP53 and liver cancer.