The findings of this study suggest that CES1 may enhance cisplatin efflux from HNSCC cells by up-regulating, ABCB1, ABCC1, ABCG2, ATP7A, and ATP7B, leading to reduced intracellular cisplatin levels and ultimately promoting cisplatin resistance in HNSCC. This evidence concerns the gene ABCG2 and head and neck squamous cell carcinoma.