GSTZ1 and malignant glioma: In a “3 + 3” study design in 15 patients (2 patients with metastatic brain tumors, 13 malignant glioma), DCA dosing was based on haplotype variation in glutathione transferase zeta 1/maleylacetoacetate isomerase (GSTZ1/MAAI), which participates in DCA and tyrosine catabolism [84].