SLC16A1 and neoplasm: Consistent with this phenomenon, the expression level of BCAT m is decreased in tumor tissues.273 In malignant gliomas, BCAT c gene expression has been reported to be positively correlated with M2-type macrophages and Treg markers,274 and GBM cells with high BCAT c expression can excrete BCKAs through monocarboxylate transporter 1 (MCT1).