LDHA and head and neck squamous cell carcinoma: It is well‐established that cancer stem cells (CSCs) play a significant role in cisplatin resistance, and increased aldehyde dehydrogenase (ALDH) activity has been observed in CSCs derived from both human primary HNSCC tissues and cell lines.[22, 23, 24] Thus, we first evaluated the effects of SQLE depletion on the cancer stemness in HNSCC using ALDEFLUOR assay and sphere formation assay.