Lu et al.9 and Hur et al.10 showed that the inactivation of GADD45α sensitized epithelial cancer cells and hepatoma cells, respectively, to radiation treatment, whereas Zhang et al.11 and Asuthkar et al.12 reported that the overexpression of GADD45α enhanced the sensitivity of squamous cell carcinoma of the tongue and medulloblastoma cells, respectively, to radiation treatment. This evidence concerns the gene GADD45A and squamous cell carcinoma.