Global metabolic profiling of pancreatic cells in vitro upon GLS1 inhibition did not identify specific pathways involved in glutamate production upon GLS1 inhibition.6 Moreover, a recent study showed cancer cells to have different metabolic behaviors in culture as compared to in vivo tumors, especially in regards to glutamine metabolism, thereby highlighting the importance of studying cancer metabolism in the tumor microenvironment.7 The gene discussed is GLS; the disease is neoplasm.