Upregulated transcripts microsomal glutathione S-transferase (Mgst1) and aldehyde dehydrogenase 1 (Aldh1a1), together with lipocalin-2 (Lcn2), have been implicated in the immunosuppressive function of myeloid-derived suppressor cells (MDSCs) to facilitate tumour progression [55–58], while the fatty acid-binding protein 4 (Fabp4) has been strongly associated with cancer metastasis [49, 59]. Here, ALDH1A1 is linked to cancer.