GLS and cancer: The conversion of glutamine to glutamate by glutaminase (GLS1 or GLS2), which is further transformed to α-ketoglutarate (α-KG) by glutamate dehydrogenase (GLUD1 or GLUD2) or aminotransferases, promotes the TCA metabolism that contributes to sustaining the energy used for cancer cell proliferation [25,26,27].