A National Center for Toxicological Research liver cancer database (NCTRlcdb) containing 999 chemicals has been developed based on liver-specific carcinogenicity. This database was constructed with the assumption that organ-specific carcinogenicity is a cleaner endpoint for building a biological predictive model. The NCTRlcdb benefits FDA reviewers by: Facilitating the construction of cleaner and better carcinogenicity models by FDA and other organizations thus providing a means to rapidly predict carcinogenicity to aid in evaluating new chemicals submitted for approval. Serving as a prototype for other organ-specific carcinogenicity databases for better Quantitative Structure-Activity Relationships (QSAR) and toxicogenomics model prediction. In the NCTRlcdb, each chemical was assigned one of the following toxicity classifications based on studies of male and female mice and rats: liver carcinogen (273) other carcinogen (293) non-carcinogen (304) other (129) Note: Running NCTRlcdb requires an Internet connection and Java version 7 or higher installed. To install or upgrade Java please visit the Oracle Java websitedisclaimer icon. Please e-mail NCTR Bioinformatics Support with any questions or problems running NCTRlcdb.