have reported that MK-8776 (another name for the chk1 inhibitor used in this study) was able to radiosensitize p53-defective cancer cell lines, but not cell lines with wild-type p53, deriving from human non-small cell lung cancer and human head and neck squamous cell carcinomas [36]. The gene discussed is CHEK1; the disease is head and neck squamous cell carcinoma.