PFKFB4 and breast cancer: The Warburg pathway enzyme 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase 4 (PFKFB4) is a kinase of the sugar metabolism that affects gene regulation by activating transcription of the oncogenic steroid receptor coactivator-3 (SRC-3), which promotes the development of tumour metastases in breast cancer (Dasgupta et al., 2018).