To start, the Humane Society International lists some animal replacements as "cell-based studies, silicon chip biosensors, and computational systems biology models , can provide faster and more human-relevant answers to medical and chemical safety questions that animal experiments cannot provide” (About Animal Testing). Modern technology allows humans to create scenarios on computers to match results on a human, which could save time and money, author of a scientific journal titled Alternatives to Animal Testing, explains how computers can reduce animal testing by using: Mathematical models and computer simulations. generate the most enthusiasm among activists. One of the underlying principles is that the biological effects of a chemical depend on the size, shape and other characteristics of its molecules, making it possible to predict its toxicity without carrying out actual testing. The database on which such systems are based will, of course, come from animal experiments. But once the relationship between molecular structure and activity is understood, the toxicity of any new substance can be predicted with a computer rather than measured in a mouse.