While many breast cancer cell lines express high levels of GS and c-Myc, however, in one breast cell line expressing reduced levels of GS, it was found that Gln restriction activates c-Myc transcriptionally targeting thymine DNA glycosylase (TDG), which induces demethylation [98] of the GS promoter, resulting in an induction of GS express, just like treating these cells with DNA methyltransferase inhibitor Aza-dC [99]. Here, TDG is linked to breast carcinoma.