Contrary to traditional in vitro assays and animal tests, embryonic stem cells have a huge benefit because they offer the advantage to grow indefinitely in dishes yet possess the ability to differentiate to mimic embryonic development, and virtually into any kind of cells of an adult organism," said Francesco Faiola, Professor at the State Key Laboratory of Environmental Chemistry and Ecotoxicology, RCEES, CAS, lead researcher of the study group.. "For instance, they can differentiate in dishes as three dimensional aggregates called embryoid bodies resembling the early stages of embryonic development. Therefore, they can be utilized in developmental toxicity assays, without the need of animal experiments."