GLS2 and central nervous system cancer: In the case of glioma cells, the activity of this enzyme is affected leading to the accumulation of PpIX.7 Other than dysfunction in FECH, high natural levels of 5-ALA, high expression of epidermal growth factor receptor (EGFR) and EGFRvIII, IDH1 gene mutation, reduced NADPH and glutaminase-2 expression are some of the factors influencing PpIX accumulation.7–9 Despite this, there exists a certain degree of uncertainty as far as the intensity of fluorescence is concerned, bringing a level of randomness to its use routinely as a surgical adjunct and for therapy.