Cancer cells proliferate much more rapidly than healthy tissues. The increased metabolic demands of such sustained proliferation results in alterations in metabolic pathways. Therapeutic targeting of these metabolic alterations provides an exciting opportunity for developing generalizable cancer treatments. One metabolic pathway of particular interest is glutamine metabolism. Many cancers require glutamine anaplerosis to fuel the TCA cycle, which provides energy and nutrients for proliferation. Drugs targeting glutaminase, an enzyme required for glutamine anaplerosis, have shown promise in in vivo animal studies and Phase I/II clinical trials in a variety of cancers including non-small cell lung carcinoma, renal cell carcinoma, and breast cancer. However, not all cancers are sensitive to glutaminase inhibition, therefore there is a need to sensitize patients to glutaminase inhibition or identify patients that will respond to these drugs.