ToxCast utilizes a comprehensive suite of in vitro assays that measure the effect of chemicals on various biological targets. This process is part of the broader Toxicology in the 21st Century (Tox21) initiative, which seeks to revolutionize toxicology testing by integrating computational models and high-throughput screening. By collecting data on how chemicals interact with biological pathways, ToxCast can predict potential adverse outcomes without the need for animal testing.