TP53 and Cockayne syndrome: Therefore, in this current report, we build upon these previous studies and compare γ-radiation-induced DNA damage and repair between the p53 and hTERT gene regions in bladder cancer cell lines (RT4 & RT112), normal fibroblast cells (GM38) and in two Cockayne Syndrome fibroblast cell lines (CSA & CSB), which are defective in TCR.