Third, AG-120 and other allosteric wtIDH1 inhibitors developed to selectively target the mutant IDH1 isoenzyme, are actually potent wtIDH1 inhibitors in tumors due to two specific conditions present to the tumor microenvironment: low Mg2+ levels which permit stronger binding of the compounds within the allosteric site of wtIDH1, and low nutrient levels (e.g., glucose in particular) which increase cancer cell reliance on the wild-type isoenzyme. The gene discussed is IDH1; the disease is neoplasm.