ERCC1 and head and neck squamous cell carcinoma: The combination of cisplatin and XAV-939 significantly reduced the expression of the CSC marker Oct4, the nucleotide excision repair gene excision repair cross-complementing rodent repair deficiency, complementation group (ERCC1), and β-catenin. This combined treatment also heightened the genotoxic effects, as indicated by increased DNA damage and shortened telomere length. Together, cisplatin and XAV-939 contribute to genomic instability in HNSCC cells by amplifying DNA damage.