XRCC6 and hepatocellular carcinoma: On the other hand, PFKFB3‐WT and PFKFB3‐E3A/Q10A/S25A mutation obviously reduced tail moment (Figure 6E) and γ‐H2AX expression (Figure 6F), but PFKFB3‐T339A/E343A/Q363A mutation failed to decrease tail moment (Figure 6E) and γ‐H2AX expression (Figure 6F) at the 24th hour after irradiation in HCC cells compared with PFKFB3‐vector, indicating T339A/E343A/ Q363A mutation hindered the binding between PFKFB3 and Ku70, and lost the ability to protect cells from IR‐induced DNA damage.