Cell Viability. Dose-dependent decrease in viability in Normal-L, XPB-L and XPD-L lymphoblastoid cells but not in XPA-L lymphoblastoid cells following H2O2 treatment. #p < 0.05; ##p < 0.01; ###p < 0.001 compared to untreated counterparts. At higher concentrations, XPA-L exhibited significantly higher viability than Normal-L. On the contrary, XPB-L and XPD-L both exhibited significantly lower viability than Normal-L following treatment. *p < 0.05; **p < 0.01 compared to Normal-L. It is interesting to note that both XPB-L and XPD-L were also significantly less viable than XPA-L at 60 μM and higher of H2O2.