Published reports have demonstrated the therapeutic utility of α-methyl-l-tryptophan as a fairly selective inhibitor of SLC6A14 in the treatment of breast cancer (Karunakaran et al., 2011), pancreatic cancer (Coothankandaswamy et al., 2016), and colon cancer (Sikder et al., 2020). This evidence concerns the gene SLC6A14 and breast cancer.