Its ability to mediate ion-driven accumulative transport of 18 of the 20 proteinogenic amino acids makes SLC6A14 an ideal candidate transporter for upregulation in cancer and increased SLC6A14 expression has been observed in colorectal cancer [28], cervical cancer [29], estrogen receptor positive breast cancer [30] and pancreatic cancer [31]. This evidence concerns the gene SLC6A14 and breast cancer.