In a total of four expression microarray data sets having both HCC and normal liver tissues [31]–[34], three showed significantly reduced expression of KLF4 mRNA in HCC compared with normal liver tissues (p<0.001 [31], p<0.001 [32] and p<0.05 [33] in Figures 6A–6C, respectively), with down-regulation ranging from 1.17 to 2.32-fold. The gene discussed is KLF4; the disease is hepatocellular carcinoma.