Skip Navigation
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.


The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Internet Explorer is no longer a supported browser.

This website may not display properly with Internet Explorer. For the best experience, please use a more recent browser such as the latest versions of Google Chrome, Microsoft Edge, and/or Mozilla Firefox. Thank you.

COVID-19 is an emerging, rapidly evolving situation.

Get the latest public health information from CDC. Get the latest research information from NIH.

Your Environment. Your Health.

Scientists & Staff

Biomolecular Screening Branch

Branch Chief

Warren Casey, Ph.D., D.A.B.T.
Warren Casey, Ph.D.
Acting Chief, Biomolecular Screening Branch
Tel 984-287-3118
P.O. Box 12233
Mail Drop K2-16
Durham, N.C. 27709

Genetic Toxicology Group

Kristine Witt, M.S.
Kristine L. Witt, M.S.
Health Science Evaluator, Genetic Toxicology Group Leader

Tel 984-287-3208
Stephanie Smith-Roe, Ph.D.
Stephanie L. Smith-Roe, Ph.D.
Genetic Toxicology Group

Tel 984-287-3189
Fax 919-541-3647

Molecular Toxicology & Genomics Group

B. Alex Merrick, Ph.D.
B A. Merrick, Ph.D.
Acting Chief, National Toxicology Program Laboratory
Group Leader, Predictive Toxicology and Screening Group
Group Leader, Molecular Toxicology and Genomics Group
P.O. Box 12233
Mail Drop E1-05
Durham, N.C. 27709

Tel 984-287-3161
Stephen Ferguson, Ph.D.
Stephen Ferguson, Ph.D.

Tel 984-287-3128
Julie Foley
Julie F. Foley
Health Scientist

Tel 984-287-3129
Alison Harrill
Alison Harrill, Ph.D.

Tel 984-287-3138
Katelyn Lavrich
Katelyn S. Lavrich, Ph.D.
Fellow — IRTA Postdoctoral

Tel 984-287-3197
Sreenivasa Ramaiahgari, Ph.D.
Sreenivasa Ramaiahgari, Ph.D.

Tel 984-287-3173
portrait of Dahea You
Dahea You, Pharm.D., Ph.D.
Fellow — IRTA Postdoctoral

Tel 984-287-3149

Spatiotemporal Health Analytics Group

Kyle P. Messier, Ph.D.
Kyle P. Messier, Ph.D.
Stadtman Investigator

Tel 984-287-3215

Toxicoinformatics Group

Scott S. Auerbach, Ph.D.
Scott S. Auerbach, Ph.D.
Molecular Toxicologist, Toxicoinformatics Group Leader

Tel 984-287-3108
Fax 919-541-3647
Frank Chao
Frank G. Chao, Ph.D.
Computational Biologist

Tel 984-287-4066
Fax 919-541-3647
Jui-Hua Hsieh
Jui-Hua Hsieh, Ph.D.
Contractor — Bioinformatics Scientist

Tel 984-287-3142
Frederick Parham, Ph.D.
Fred Parham, Ph.D.
Mathematical Statistician
P.O. Box 12233
Mail Drop K2-17
Durham, N.C. 27709

Tel 984-287-3169
Arif Rahman
Arif Rahman, Ph.D.
Fellow — Visiting

Tel 984-287-3135
Nisha S. Snipes, Ph.D.
Nisha S. Sipes, Ph.D.
Health Science Evaluator

Tel 984-287-3187


Pierre R. Bushel, Ph.D.
Pierre R. Bushel, Ph.D.
Staff Scientist

Tel 984-287-3714
Fax 301-480-3569
Keith R. Shockley, Ph.D.
Keith R. Shockley, Ph.D.
Staff Scientist

Tel 984-287-3698

Special Volunteers

Richard S. Paules, Ph.D.
Richard S. Paules, Ph.D.
Special Volunteer

Tel 919-208-1660
to Top