SLC26A9 and head and neck squamous cell carcinoma: Supplementary Figure 10 demonstrates that SLC26A9 is a protective factor in the prognosis of HNSCC. During our research, we utilized a collection of siRNAs to inhibit the expression of SLC26A9 in SCC15 and HN30 cell lines. After 48 hours of transfection, western blot analysis confirmed the successful knockdown of SLC26A9 (Figure 7A).