OGT and breast cancer: Previously, chemical inhibition of OGT using acetyl-5S-GlcNAc in MCF-7 breast cancer cells was reported to cause a reduction in the percentage of S-phase cells without affecting DNA replication rate, indicative of impaired G1/S phase transitioning as opposed to prolonged S-phase duration, although the authors were unable to determine which O-GlcNAc signalling nodes were dysregulated to convey this effect [28].