 Computer models have been constructed to model human metabolism, to study plaque build-up and cardiovascular risk, and to evaluate toxicity of drugs, tasks for which animals are also used.In 2007, US researchers using the world's fastest computer at the time, BlueGene L, modeled half a mouse brain for just 10 seconds.However, due to limitations in computing power, the simulation could only be run at 1/10th the speed of an actual mouse brain.