A subset of SLC family members, including SLC3A2, SLC7A6, SLC7A11, SLC7A5, SLC7A8, SLC43A1, LCN2, SLC7A9, SLC7A7, BSG, and SLC7A10, are frequently overexpressed in multiple cancer types and are strongly associated with tumor progression, metastasis, and therapy resistance [5,6,7,8]. This evidence concerns the gene CCL21 and cancer.