Foy et al. [80] identified thirteen differentially expressed genes (including CCND1) that are significantly associated with the radioresistance of HNSCC cells and patients, and 12 of the 84 genes involved in DNA-damage signaling and repairing were under-expressed in radioresistant HNSCC cells after irradiation [37]. The gene discussed is CCND1; the disease is head and neck squamous cell carcinoma.