MCT1 and MCT4 have been extensively described at the plasma membrane of solid tumours as major players in the acid-resistant phenotype of tumour cells [22, 23] and attractive targets for cancer therapy alone or in combination with other drugs targeting metabolism [24], MCT2 appears to contrast with this well-known and stablished function of MCTs 1 and 4 in glycolysis. This evidence concerns the gene SLC16A1 and cancer.