Frequency of XPC, XPD, and XPG NER protein localization in XP, XP/TTD, and TTD cells at 0.1 hr, 0.5 hr, and 24 hr after UV irradiation. A total of 50 nuclei were scored as being with (positive) or without (negative) DNA damage or NER protein localization at the indicated time points postirradiation. A: XPC localization. B: XPD localization. C: XPG localization. Where shown, error bars indicate the SEM of at least two independent counts.*p<0.001 significant difference between patient cell count and normal cell count at the equivalent time postirradiation. Bar numbers: 1, Patient AG13145; 2, Patient XP34BE; 3, Patient XP17BE; 4, Patient XPTTD306BE; 5, Patient TTD331BE; 6, Patient TTD351BE; 7, Patient TTD355BE; 8, Patient TTD1VI; and 9, Patient TTD1VI [XPD-GPF]+.