We stably transduced mCherry-tagged wild-type XPF (WT) and three disease-associated mutant XPF cDNA constructs, encoding P379S mutant XPF, associated with mild XP, R799W mutant XPF, associated with more severe XP including progressive neurodegeneration, and C236R mutant XPF, associated with the most severe XPCS complex, in GFP-XPB KI XPF KO U2OS cell lines (Fig. 2E)37,41–43. Here, ERCC4 is linked to xeroderma pigmentosum.