PFKFB4 and breast cancer: Moreover, the PFK-2 isoform PFKFB4 directly phosphorylates and activates steroid receptor co-activator-3 (SRC-3), and the PFKFB4–SRC-3 axis drives primary growth and metastasis of basal-subtype breast cancer cells in a mouse xenograft model (Dasgupta et al., 2018).