GLS and cancer: Glutamine consumption is often increased in malignant tumors and the inhibition of intracellular glutaminase (GLS) activity – which converts glutamine into glutamate – has been shown to reduce proliferation and angiogenesis of tumor cells of different origin (Draoui et al., 2017; Zhao et al., 2017; Bruntz et al., 2019; Restall et al., 2020).