While chemicals provide many benefits, many chemicals have adverse effects in some cases. Toxicology plays an important role in risk assessment of chemicals for carcinogenicity, neurotoxicity, reproductive toxicity, developmental toxicity, genetic toxicity, immunotoxicity and general toxicity. The risk assessment can help prevent health hazards and it is also utilized for risk management. In our laboratory, we are developing the method of risk assessment for new substances such as nanomaterials, which have different properties from general chemicals. In addition, we are developing new low-toxic anti-cancer drugs, which are derivatives of component from natural products, using in vitro, in vivo and in silico analyses. Associated with founding of the Institute of Brain Science, we will study wider research fields.