GLS and central nervous system cancer: Inhibitors of additional metabolic enzymes in gliomas, such as glutaminase (GLS1) via CB-839, fatty acid synthase (FASN) via TVB-2640, isocitrate dehydrogenases (IDH) 1-2 via ivosidenib (AG-120) and vorasidenib (AG-881), and IDO-1 via indoximod (1-MT) and epacadostat (INCB024360) (120).