The Viracept-EMS case: impact and outlook.

This perspective first considers the potential impact of the Viracept-EMS case in the framework of the current understanding of the low-dose effects of DNA-reactive chemicals and the approaches used to estimate health risks from genotoxins occurring as impurities in pharmaceutical products or as contaminants in the environment or workplace. It also presents an outlook on the nature of additional research building upon the Viracept-EMS case to test assumptions underlying thresholded dose-response relationships and to establish biologically based risk assessment models in lieu of default models for DNA-reactive compounds.