Recent developments in frameworks to consider human relevance of hypothesized modes of action for tumours in animals.

This paper summarizes recent developments in the continuing evolution of Human Relevance Frameworks to systematically consider the weight of evidence of hypothesized modes of action in animals and their potential human relevance for both cancer and non-cancer effects. These frameworks have been developed in initiatives of the International Life Sciences Institute Risk Sciences Institute and the International Programme on Chemical Safety engaging large numbers of scientists internationally. They are analytical tools designed to organize information in hazard characterization as a basis to clarify the extent of the weight of evidence for mode of action in animals and human relevance and subsequent implications for dose-response. They are also extremely helpful in identifying critical data gaps. These frameworks which are illustrated by an increasing number of case studies, have been widely adopted into international and national guidance and assessments and continue to evolve, as experience increases in their application. Published 2008 Wiley-Liss, Inc.