Genes responsible for the maintenance of cell walls in yeast have been shown to be responsible for angiogenesis in vertebrates. Tiabendazole serves to block angiogenesis in both frog embryos and human cells. It has also been shown to serve as a vascular disrupting agent to reduce newly established blood vessels. Tiabendazole has been shown to effectively do this in certain cancer cells 
The substance appears to have a slight toxicity in higher doses, with effects such as liver and intestinal disorders at high exposure in test animals (just below LD50 level). Some reproductive disorders and decreasing weaning weight have been observed, also at high exposure. Effects on humans from use as a drug include nausea, vomiting, loss of appetite, diarrhea, dizziness, drowsiness, or headache; very rarely also ringing in the ears, vision changes, stomach pain, yellowing eyes and skin, dark urine, fever, fatigue, increased thirst and change in the amount of urine occur. Carcinogenic effects have been shown at higher doses.
^Grenda, V. J.; Jones, R. E.; Gal, G.; Sletzinger, M. (1965). "Novel Preparation of Benzimidazoles from N-Arylamidines. New Synthesis of Thiabendazole1". The Journal of Organic Chemistry30: 259. doi:10.1021/jo01012a061.edit
^Brown, H. D.; Matzuk, A. R.; Ilves, I. R.; Peterson, L. H.; Harris, S. A.; Sarett, L. H.; Egerton, J. R.; Yakstis, J. J.; Campbell, W. C.; Cuckler, A. C. (1961). "Antiparasitic Drugs. Iv. 2-(4'-Thiazolyl)-Benzimidazole, A New Anthelmintic". Journal of the American Chemical Society83 (7): 1764. doi:10.1021/ja01468a052.edit
^Tocco, D. J.; Buhs, R. P.; Brown, H. D.; Matzuk, A. R.; Mertel, H. E.; Harman, R. E.; Trenner, N. R. (1964). "The Metabolic Fate of Thiabendazole in Sheep1". Journal of Medicinal Chemistry7 (4): 399. doi:10.1021/jm00334a002.edit