LIG4 and cancer: Nevertheless, a Lig4−/−p53−/− cell line had a higher sensitivity to high-LET radiation than a Lig4+/+p53−/− cell line, suggesting that LET-induced DNA damage is partially repaired through LIG4309 McKay et al.310 screened tissues from a unique bank of samples from radiosensitive cancer patients for expression defects in major DSB proteins such as LIG4.