Before his concepts were applied, it was generally considered to be very difficult or even impossible to obtain reproducible results in medical research using laboratory animals, mainly due to the traditional consensus that the animals are living organisms with individual differences.

He has completely changed this out-dated paradigm in medical research by establishing comprehensive animal experimentation systems.

To this end, the 3R (Replacement, Refinement, and Reduction of Animals in Research) principle proposed by Russell and Burch in 1959 was adopted.

The number of animals used can also be reduced by using mice subject to stricter quality control than monkeys.

Dr. Nomura is currently Director of the Central Institute for Experimental Animals, Japan, that he founded in 1952, to improve the level of medical research.