PTK2B and cancer: In addition, kaempferol can target many molecular-signaling pathways such as vascular endothelial growth factor (VEGF), signal transducer and activator of transcription (STAT), p53 (a tumor suppressor protein), PI3K-PKP (phosphoinositide-3-kinase–protein kinase B), NF-κB (Nuclear factor kappa-light-chain-enhancer of activated B cells), and ERRα (estrogen-related receptor α) signaling pathways, depending on what cancer cell lines were used.