Based on the finding that BRCA1 represents another positive transcriptional regulator of the human XPC gene, a sequential scenario has been proposed for an involvement of XPC in the progression of breast or ovarian cancer, where the loss of BRCA1 restricts the initiation of GG-NER activity by XPC protein and, therefore, causes an accumulation of DNA damage and mutations in the p53 gene, which in turn leads to an even more pronounced GG-NER defect and genome instability [100]. The gene discussed is XPC; the disease is ovarian cancer.