NICEATM and EPA scientists built an AOP for quantitative prediction of developmental vascular toxicity. This AOP was then applied to ToxCast HTS data to develop predictions of chemicals’ potential to disrupt angiogenesis, or blood vessel development (Saili et al. 2019). The predictions were evaluated for 38 compounds tested across a suite of functional assays for the angiogenic cycle, including assays in complex cell systems, virtual tissues, and small model organisms. The results serve to boost confidence in the capacity of HTS data to predict developmental vascular toxicity.