Interestingly, Wozny et al., showed that under hypoxia, silencing of HIF-1α that is translocating to the nucleus significantly radiosensitizes HNSCC and cancer stem cell subpopulations to photons and C-ion exposures because of decreased DSB detection by the ATM protein and decreased DSB repair by HR and NHEJ [288]. This evidence concerns the gene HIF1A and cancer.