CB-839 is a potent and selective inhibitor of glutaminase, an enzyme involved in the metabolism of glutamine in cancer cells. It is primarily investigated for its role in cancer therapy, particularly in tumors that rely heavily on glutamine for growth and survival. By blocking glutaminase, CB-839 disrupts energy production and biosynthetic pathways in cancer cells, leading to reduced tumor growth. It has shown promising activity in preclinical and clinical studies against various cancers, including triple-negative breast cancer, non-small cell lung cancer, and certain hematologic malignancies like acute myeloid leukemia. CB-839 is often used in combination with other anticancer agents, such as chemotherapy or targeted therapies, to enhance efficacy and overcome resistance. Its application is especially relevant in tumors with specific genetic mutations, such as KEAP1 or NRF2 alterations, which increase dependency on glutamine metabolism. Due to its targeted mechanism, CB-839 represents a strategy in metabolic therapy for cancer, aiming to exploit the unique metabolic vulnerabilities of tumor cells while sparing normal tissues.