For example, silencing of 6-Phosphofructo-2-Kinase/Fructose-2,6-Biphosphatase 4 (PFKFB4), a protein responsible for regulating carbon entering glycolysis, only induced apoptosis in prostate cancer lines derived from metastasis when grown in low serum. The gene discussed is PFKFB4; the disease is prostate cancer.