CDK4 and hepatocellular carcinoma: In support of the role of NC in hepatocellular cancer, one group validated that NC inhibited tumor growth, through blocking STAT3, ERK (extracellular signal-regulated kinase), and SHH (Sonic Hedgehog) pathways, and suppressed the expression of Bcl-2 (B cell lymphoma 2), CDK4 (cyclin-dependent kinase 4), VEGF-A (vascular endothelial growth factor A), VEGFR2 (VEGF receptor 2), and Cyclin D1 in liver cancer.18