SLC6A14 and neoplasm: Glutamine‐addicted tumor cells competitively consume glutamine to indirectly polarize macrophages to the pro‐tumorigenic M2 subtype.[79] Interestingly, SLC6A14 expression in tumour tissues has been found to be positively correlated with tumour‐associated M2 macrophages.[61] Therefore, selectively targeting SLC6A14 in tumor cells may not only inhibit the self‐renewal of CSCs but also alleviate glutamine competition to repolarize macrophages back to the anti‐tumorigenic M1 subtype in the TME.