IDH1 and central nervous system cancer: IDH1-mutant human glioma cells (U87MG) with reduced levels of NADPH showed enhanced PpIX fluorescence after incubation with 5-ALA compared with their wild-type counterparts.66 Conversely, overexpression of GLS2 in glioma cells (T98G, LN18, U87MG) increased the levels of NADPH but reduced 5-ALA-induced fluorescence.67