Expression of SIP1 in HCC cell lines and tumors. (A) SIP1 expression is detected in 14 HCC cell lines by multiplex semi-quantitative RT-PCR. GAPDH is used as an internal control. Amplicons corresponding to SIP1 and GAPDH are 132 bp and 611 bp, respectively. A negative control without a DNA template is included. Bands lower than 100 bp in most of the cell lines and negative control sample are primer dimers. M: marker. (B) SIP1 mRNA expression in HCC tumors relative to tumor-adjacent and normal tissues is analyzed by quantitative RT-PCR. Relative mRNA levels of SIP1 normalized to TBP are represented. Patients are grouped depending on tumor stage (GI-GIV). Clinicopathological characteristics of patients (C9-E9) are given in Additional file 1. Standard deviations of two independent experiments are shown.