To verify whether XPA is a cisplatin resistance factor in NPC cells, we firstly tested the half maximal inhibitory concentration (IC50) of cisplatin by MTT assay after knocking down XPA expression in NPC cell line HONE1 and CNE1 cells, or overexpressing XPA in CNE1 and CNE2 cells. Here, XPA is linked to nasopharyngeal carcinoma.