However, development and growth of breast cancer were notably suppressed in a murine mammary tumor virus-polyoma middle tumor-antigen (MTV-PyMT) model deficient in SLc6a14 as compared to MTV-PyMT mice expressing SLc6a14 [54], indicating the potential tumor-promoting activity of ATB0,+ in the mammary gland. This evidence concerns the gene SLC6A14 and breast cancer.