SLC16A1 and cancer: Inhibition of MCT1 resulted in oxidative cancer cells switching to glycolysis from lactate oxidation.40 Furthermore, the lactate and glutamate secreted by cancer cells are utilized and metabolized by cancer‐associated fibroblasts (CAFs) to synthesize lighter glutamine isotopologues for glutaminolysis and nucleotide synthesis in cancer cells.43 The symbiotic relationship between oxidative, glycolytic tumour cells and CAFs is formed by lactate.