TIA1 and hepatocellular carcinoma: Because TIA1 upregulation does not completely explain the suppression of IGFBP3 in pediatric liver tumors (Figure 1F), we examined a CpG island located in the IGFBP3 promoter region for differential methylation in established HB cell lines, namely HUH6, HepT3, HepT1, and HepG2, and the non-hepatitis B virus-associated HCC cell line HUH7, as well as normal liver by means of bisulfite sequencing.