GLS and cancer: The results of a metabonomics study showed that glutaminase expression was higher in primary and metastatic HNSCC tissues, tumourspheres, and cancer stem cells than in control samples, and that exogenous glutamine induced stemness via glutaminase.13 Xin Li’ s team explored the strategy of targeting cellular glutamine metabolism to reduce HNSCC growth, which was suggested to be effective, especially in combination with metformin.14