Gln metabolism in AML in tumor microenvironment. (A) Tumor cells avidly consume Gln to fuel biosynthesis and proliferation. GLS converts Gln to Glu, which is a necessary step for Gln to enter the TCA cycle. BCAT1, a cytosolic aminotransferase for BCAAs (leucine, isoleucine, and Val), is a critical enzyme that initiates the catabolism of BCAAs and results in the production of Glu. (B) Consumption of Gln by tumor cells deprives immune cells of this critical nutrient. GLS inhibitor blocks Gln consumption by tumor cells and elevates Glu in the tumor microenvironment supporting immune cell function.