Three Rs in mutation research -- From in vivo to in silico evaluation --

Many genotoxicity assay systems have been developed and introduced for safety assessment of chemicals. More than a half of them are in vitro systems therefore we can say that the field of genotoxicity started from the alternatives of animal experiments. Our respect to the 3Rs, we are introducing the in silico evaluation system, reconsidering the interpretation of positive outcomes from the in vitro assay systems based on the weight of evidence, and incorporating in vivo genotoxicity assay systems into general toxicological studies. These attempts replace existing systems with new systems without using any animals, reduce number of animals because of reduction of irrelevant in vitro positives, and share animals with other study as multiple endpoint assay systems.