Response to Gribaldo and Hartung: New hepatocytes for toxicology?

The identification of chemical and physical agents potentially hazardous for human health remains a challenge. On one hand, society demands strict controls to ensure that new chemicals come into contact with humans and animals only when they have been proved absolutely safe; and on the other hand, the identification of non-toxic compounds is a time- and money-consuming process because cheap high-throughput assays are not yet available. In addition, an animal-based testing step required to fulfil scientific standards clashes with the personal beliefs of a large strata of the population.