(A) AFP mRNA expression by reverse transcription-quantitative polymerase chain reaction in an independent cohort of 10 paired HBs and adjacent non-tumor tissues with complementary DNA (P<0.01; paired Student's t-test). (B) Correlation analysis of AFP mRNA expression and percentage of DNA methylation in 10 HB primary tissues, analyzed by two-tailed Pearson's correlation test. AFP, alpha-fetoprotein; HB, hepatoblastoma; NT, non-tumor; mRNA, messenger RNA.