NICEATM is mapping assay targets used in Tox21 and the EPA ToxCast programs to known modes of action for developmental toxicity, acute toxicity, and carcinogenicity based on established modes of action from literature. The assay mappings are used in ICE to facilitate targeted access to the Tox21 data in ICE tools. This mapping draws on established ontologies and controlled vocabularies such as the NCI Metathesaurus and UMLS Metathesaurus to promote the interoperability of ICE data with partners.