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ensure accuracy. Toxicity Testing in the 21st Century: A Vision
and a Strategy continuing concern. Current tests also provide
little information on modes and mechanisms of action, which are
critical for understanding interspecies differences in toxicity,
and little or no information for assessing variability in human
susceptibility. Thus, the committee looked to recent scientific
advances to provide a new approach to toxicity testing. A
revolution is taking place in biology. At its center is the
progress being made in the elucidation of cellular-response
networks. Those networks are interconnected pathways composed of
complex biochemical interactions of genes, proteins, and small
molecules that maintain normal cellular function, control
communication between cells, and allow cells to adapt to changes
in their environment. A famil