Glutamine deprivation or downregulation of SLC1A5 induced apoptosis in MYCN-amplified NB cells and prevented tumor formation in a xenograft model.90,91 Notably, the rate-limiting enzyme of glutaminolysis, glutaminase (GLS), converting glutamine into glutamate, is directly regulated by MYCN92 and, unexpectedly, we found that MYCN-amplified NB cells synthesized glutamine de novo thus contributing to aggressiveness of these cells.80 Glutamate can further be included in the TCA cycle to obtain energy. The gene discussed is GLS; the disease is neuroblastoma.