In this sense, higher O-GlcNAc levels induce the transcription of several proliferative genes through different signaling routes [81]; e.g., in breast cancer cells, the Ras–Raf–MEK–ERK signaling pathway is affected, because O-GlcNAcylation avoids the degradation of MEK2, which extends its proliferative effects [82]. The gene discussed is MAP2K2; the disease is breast carcinoma.