Abstract. Background Nuclear factor kappa-B (NFĸB) is a transcription factor playing a crucial role in malignant diseases (1-4). Upregulation of NFĸB activity is detected in various human tumours (5-7), including pancreatic adenocarcinoma (8), breast cancer (9), and melanoma (10), where it may contribute to malignant behaviour. In particular, NFĸB activation has been associated with cancer development and progression (5, 11), and may inhibit apoptosis and favour cancer cell proliferation, invasion, angiogenesis, and metastasis (12, 13). Importantly, increased NFĸB activation may induce tumour immune escape and chemotherapy resistance (14-16). Chemotherapy-induced cellular stress, in turn, might further increase NFĸB activity of tumour cells, protecting them from chemotherapy-induced apoptosis (17)(18)(19). Therefore, NFĸB signaling pathways could serve as potential targets for cancer therapy.Vanillin (4-hydroxy-3-methoxybenzaldehyde; compound 10, Table I) is a major component of the bean and pod of some plant species of the Vanilla genus, and is also synthesized on a large scale for use as a flavouring agent in food, fragrance and pharmaceutical industries. Multiple biological effects have been documented for vanillin. It exhibits antioxidant (20, 21), antimicrobial (22), analgesic (23, 24) and anti-sickling (25) properties. It was also proven to be an anticarcinogen in rats (26) and an antimutagen in a variety of in vitro models (27)(28)(29). Vanillin is relatively noncytotoxic towards cultured mammalian cells, but does potentiate the cytotoxicity of some DNA-damaging agents, including cisplatin (30) and mitomycin C (31), a property which correlates with its ability to impair DNA double-strand break repair via inhibition of DNA protein kinase (30). Although unable to suppress primary tumour growth itself, vanillin was found to exert anti-metastatic activity in the 4T1 mouse mammary carcinoma spontaneous metastasis model, and to inhibit tumour cell invasion and migration in vitro 5743