Interestingly, the authors demonstrated the presence of ω-amidase, GTK (annotated as kynurenine aminotransferase 1 (KAT1)) and GTL (annotated as kynurenine aminotransferase 3 (KAT3)) in typical cancer cell lines, such as A-431, U-251MG and U2OS [8]. Here, KYAT1 is linked to cancer.