When asparagine levels are low, asparagine synthetase (ASNS) catalyzes transamination of glutamine to aspartate, resulting in production of glutamate and asparagine. Acute lymphoblastic leukemia (ALL) cells generally exhibit little to no detectable ASNS expression, which makes ALL cells auxotrophs for asparagine and renders them particularly sensitive to asparagine depletion. Asparaginase enzymes, short and long-acting, that are approved for treatment of adult and children with ALL are derived from Escherichia coli and Erwinia chrysanthemi.