PDK1 and hepatocellular carcinoma: Furthermore, we demonstrated that aside from eliciting a 59% decline in the viability of PDK1high Mahlavu cells, siRNA-mediated loss-of-PDK1 function (siPDK1) enhanced their sensitivity to 2 Gy IR by a significant 80%; similarly in synergism with siPDK1, the cytocidal effect of 2 Gy IR was increased to 97% from 42% alone in PDK1low Huh7 cells, and to 93% from 26% alone in PDK1moderate Hep3B cells (Figure 2B), thus, indicating a vital role for PDK1 expression and/or activity in the radiosensitivity of HCC cells.