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Your Environment. Your Health.

Robert Sills, D.V.M., Ph.D., DACVP, Fellow IATP

Robert C. Sills, D.V.M., Ph.D.
Robert C. Sills, D.V.M., Ph.D.
Chief, Cellular & Molecular Pathology Branch, Interim Group Leader, Image Analysis Group
Tel 984-287-3839
P.O. Box 12233
Mail Drop B3-06
Durham, N.C. 27709

Robert C. Sills, D.V.M., Ph.D., DACVP, Fellow IATP, is a senior staff scientist/pathologist and Chief of the Cellular and Molecular Pathology Branch (CMPB) in the Division of the National Toxicology Program (DNTP) at the National Institute of Environmental Health Sciences (NIEHS). He oversees 6 groups that are responsible for Anatomical and Clinical Toxicologic Pathology Evaluations, Molecular Pathology Investigations, Laboratory Animal Medicine, and Core Pathology Laboratories (Pathology Support, Special Techniques) in the National Toxicology Program (NTP) and NIEHS.  

Additionally, he is an adjunct professor in the Department of Toxicology at the University of North Carolina School of Medicine at Chapel Hill, North Carolina, and in the Department of Population Health and Pathobiology, College of Veterinary Medicine, North Carolina State University.  

His research interests include the study of molecular mechanisms of non-cancer and cancer diseases related to environmental exposures.  Of special interest is in the area of neuropathology evaluations.  He is a member of the American College of Veterinary Pathologists (ACVP), Society of Toxicologic Pathology (STP), and the American Veterinary Medical Association (AVMA). He presently serves on the Executive Council for the Society of Toxicologic Pathology and is the associate editor for the environmental pathobiology section of Veterinary Pathology.  

Sills has served as the President of the Society of Toxicologic Pathology (2013-2014). He chaired STP annual meeting sessions on the human genome, implications for toxicologic pathology and carcinogenesis, and a session on cellular and molecular neurocarcinogenesis, and toxicologic pathology of the nervous system. Also, he co-chaired the International Life Sciences Institute (ILSI) seminar series on current issues in neuropathology.

Sills received his Doctor of Veterinary Medicine degree from Tuskegee University (1984) and completed an internship in anatomical pathology from Tuskegee University (1985) and a combined residency/Ph.D. in toxicologic pathology from Michigan State University (1991). He is a diplomate of the American College of Veterinary Pathologists.

Selected Publications


  1. Yamashita, H, Hoenerhoff, MJ, Peddada, SD, Sills, RC, Pandiri, AR. Chemical Exacerbation of Light-induced Retinal Degeneration in F344/N Rats in National Toxicology Program Rodent Bioassays. Toxicologic pathology 2016 44(6):892-903. [Abstract]
  2. Cesta MF, Malarkey DE, Herbert RA, Brix A, Hamlin MH 2nd, Singletary E, Sills RC, Bucher JR, Birnbaum LS. The National Toxicology Program Web-based nonneoplastic lesion atlas: a global toxicology and pathology resource. Toxicologic pathology 2014 42(2):458-460. [Abstract]
  3. Rao DB, Jortner BS, Sills RC. Animal models of peripheral neuropathy due to environmental toxicants. ILAR journal / National Research Council, Institute of Laboratory Animal Resources 2014 54(3):315-323. [Abstract]
  4. Rao DB, Little PB, Sills RC. Subsite awareness in neuropathology evaluation of National Toxicology Program (NTP) studies: a review of select neuroanatomical structures with their functional significance in rodents. Toxicologic pathology 2014 42(3):487-509. [Abstract]
  5. Schmidt SP, Jokinen MP, Law JM, Pandiri AR, Weddle DL, Wolf JC, Sills RC. Environmental pathobiology and global opportunities. 2013 Vet Pathol. 50:733. [Abstract]
  6. Bolon B, Garman RH, Pardo ID, Jensen K, Sills RC, Roulois A, Radovsky A, Bradley A, Andrews-Jones L, Butt M, Gumprecht L. STP position paper: Recommended practices for sampling and processing the nervous system (brain, spinal cord, nerve, and eye) during nonclinical general toxicity studies. Toxicol Pathol. 2013 41:1028-48. [Abstract]
  7. Rao, D.B., Little, P.B., Malarkey, D.E., Herbert, R.A., Sills, R.C. Histopathological Evaluation of the Nervous System in Routine National Toxicology Program Rodent Studies: A Modified Approach. Toxicologic Pathology. 39(3):463-470, 2011. [Abstract]


  1. Hayes S, Pandiri AR, Ton TV, Hong HH, Clayton NP, Shockley KR, Peddada SD, Gerrish K, Wyde M, Sills RC, Hoenerhoff MJ. Renal Cell Carcinomas in Vinylidene Chloride-exposed Male B6C3F1 Mice Are Characterized by Oxidative Stress and TP53 Pathway Dysregulation. Toxicologic pathology 2016 44(1):71-87. [Abstract]
  2. Hong HH, Hoenerhoff MJ, Ton TV, Herbert RA, Kissling GE, Hooth MJ, Behl M, Witt KL, Smith-Roe SL, Sills RC, Pandiri AR7. Kras, Egfr, and Tp53 Mutations in B6C3F1/N Mouse and F344/NTac Rat Alveolar/Bronchiolar Carcinomas Resulting from Chronic Inhalation Exposure to Cobalt Metal. Toxicologic pathology 2015 43(6):872-882. [Abstract]
  3. Blackshear PE, Pandiri AR, Nagai H, Bhusari S, Hong L, Ton TV, Clayton NP, Wyde M, Shockley KR, Peddada SD, Gerrish KE, Sills RC, Hoenerhoff MJ. Gene expression of mesothelioma in vinylidene chloride-exposed F344/N rats reveal immune dysfunction, tissue damage, and inflammation pathways. 2015 Toxicologic Patholology 43(2): 171-185. [Abstract]
  4. Bhusari S, Malarkey DE, Hong HH, Wang Y, Masinde T, Nolan M, Hooth MJ, Lea IA, Vasconcelos D, Sills RC, Hoenerhoff MJ. 2014. Mutation spectra of Kras and Tp53 in urethral and lung neoplasms in B6C3F1 mice treated with 3,3’,4,4”-tetrachloroazobenzene. Toxicology Pathology 42(3):555-64. [Abstract]
  5. Hoenerhoff MJ, Pandiri AR, Snyder SA, Hong HH, Ton TV, Peddada S, Shockley K, Witt K, Chan P, Rider C, Kooistra L, Nyska A, Sills RC. Hepatocellular carcinomas in B6C3F1 mice treated with Ginkgo biloba extract for two years differ from spontaneous liver tumors in cancer gene mutations and genomic pathways. Toxicol Pathol Aug; 2013 41(6):826-41. [Abstract]
  6. Pandiri AR, Sills RC, Ziglioli V, Ton TV, Hong HH, Lahousse SA, Gerrish KE, Auerbach SS, Shockley KR, Bushel PR, Peddada SD, Hoenerhoff MJ. Differential transcriptomic analysis of spontaneous lung tumors in B6C3F1 mice: comparison to human non-small cell lung cancer. Toxicol Pathol. 2012 40:1141. [Abstract]
  7. Pandiri AR, Sills, RC, Hoenerhoff, MJK,Peddada, SD, Ton,T-Vt, Hong H-H, Flake, GP, Malarkey, DE, Olsen, GR, Pogribny, I, Walker, NJ, and Boudreau MD. (2011) Aloe vera nondecolorized whole leaf extract-induced large intestinal tumors in F344 rats share similar molecular pathways with human sporadic colorectal tumors.  Toxicologic Pathology 39(7):1065-74
  8. Hoenerhoff MJ, Pandiri AR, Lahousse SA, Hong HH, Ton TV, Auerbach SS, Gerrish K, Bushel PR, Shockley KR, Peddada SD, Sills RC. Global gene expression profiling of spontaneous hepatocellular carcinoma in B6C3F1 mice: similarities in the molecular landscape with human liver cancer. Toxicologic Pathology 2011 39(4):678-699. [Abstract]
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