(C) UV-RRS, a measure of transcription-coupled repair of UV-induced lesions. Number of experiments: n = 7 (XpdTTD/TTD), n = 2 (XpdTTD/KO), n = 4 (XpdTTD/†XPCS ), n = 2 (XpdTTD/†XP ); 1–2 cell lines per genotype were included in each experiment.