However, upon examination of CpG island methylation of Rab1A promoter in two HCC cell lines (MHCC97H and PLC/PRF/5) with high Rab1A expression, and in two immortalized liver cell lines (LO2 and QSG-7701) with low Rab1A expression, we did not find significant DNA methylation in any of the HCC cell lines (Figure 1E and 1F), suggesting that methylation does not contributes significantly to aberrant Rab1A expression. The gene discussed is RAB1A; the disease is hepatocellular carcinoma.