Then, following overexpression of TMEM27 in HNSCC cells (Fig. S6B), TEM analysis revealed that irradiated TMEM27-overexpressing Fadu cells exhibited shrunken mitochondria with increased membrane density (Fig. S6C) and colony formation assays demonstrated that overexpression of TMEM27 enhanced the efficacy of radiotherapy in Fadu and HN8 cells (Fig. S6D). Here, CLTRN is linked to head and neck squamous cell carcinoma.