To date traditional toxicity testing has relied heavily on in-life animal studies that are expensive and restrictive with regards to very important ethical implications. In addition, these studies often yield data that are not relevant to human exposures or biological responses due to intra-species variations, necessitating the requirement for further testing or candidate (drug) abandonment in late development stages. There is increasing global pressure from regulatory agencies, the general public, and the scientific community to develop in vitro alteatives for toxicity testing that can be utilized for mechanistic dose response hazard identification prior to embarking on small well designed and absolutely necessary in vivo studies.