SLC16A3 and cancer: Consistent with the key importance of MCT4 for the survival of tumor cells, its selective inhibition to block lactic acid efflux appears to be a promising therapeutic strategy against highly glycolytic malignant tumors (Choi et al., 2016; Todenhöfer et al., 2018; Choi et al., 2018; Zhao et al., 2019b).