PFKFB4 and breast carcinoma: In fact, sulforaphane has been shown to decrease HK-II and PKM2 levels in breast cancer cell lines [51] and 6-phosphofructo-2-kinase/fructose-2,6-biphosphatase4 (PFKFB4) via reducing HIF-1α expression in hepatocellular carcinoma cells [52].