Study Team Members

Principal Investigator

Douglas Stewart, M.D., an internist and medical geneticist, is the principal investigator of the DICER1 study and has a special interest in familial cancer syndromes.

Clinical Team

Margarita Aryavand, M.S.N., C.F.N.P., nurse practitioner and captain of the U.S. Public Health Service, assesses the genetic causes and clinical features of RASopathies and examines the role of genetic and environmental factors in the etiology of cancer and related conditions.

Mary Lou McMaster, M.D., senior clinical specialist and captain in the U.S. Public Health Service, characterizes the clinical spectrum of DICER1 families and explores genotype-phenotype correlations.

Scientific Team

Ana Best, Ph.D., a mathematical statistician in NCI’s Division of Cancer Treatment and Diagnosis, has played a key role in developing estimates of cancer risk in people with a disease-causing DICER1 variant.

Jung Kim, Ph.D., staff scientist, studies the population genetics and phenotype of DICER1 and the associated miRNA processing genes; she also analyzes somatic genomic data of DICER1-associated malignancies.

Jessica Hatton, M.S., C.G.C., a genetic counselor who works to interpret the clinical significance of different DICER1 genetic variants.

Special Volunteer

Lauren Vasta, M.D., a Major in the Army and the Chief of Pediatric Hematology and Oncology at Tripler Army Medical Center, serves the study as a Clinical Fellow in a special volunteer status. Her current DICER1 interests involve examining the phenotype of DICER1-carriers and examining associated underlying genetics.

Scientific Support

Cecilia Higgs, M.H.S. program manager, leads the regulatory matters of the study and manages the study files, including the protocol, consent documents, and submissions to the Institutional Review Board.

Study Support

Laura Harney, R.N., B.S.N., is a registered nurse who supports cancer genetics research.

Ann Carr, M.S., C.G.C., is a genetic counselor with many years of experience in both cancer and pediatric genetics. She also serves as a research coordinator who will manage referrals for this study.

Stephanie Steinbart, R.N., M.P.H., was a research nurse who served as CGB’s referral nurse. She retired in January 2023 after more than 20 years of dedication.


The DICER1 study has been at the forefront of an exciting interdisciplinary collaboration, leading to new discoveries and insights in the causes and importance of early interventions for DICER1-related disorders. The NCI team and our collaborators meet monthly via WebEx to discuss new findings and patient study updates. Our collaboration extends across the country and includes the following people:

Kris Ann Schultz, M.D., is a pediatric oncologist at Children’s Minnesota with a special interest in ovarian and testicular tumors. She is the Director of the International Pleuropulmonary Blastoma/DICER1 Registry

Ashley Hill, M.D., is chief of Pathology at Children’s National Medical Center. She led the study team credited with discovering variants in the DICER1 gene that can cause PPB and related tumors.

Yoav Messinger, M.D., is a pediatric oncologist at Children’s Minnesota with many years of experience treating children with PPB.

Louis “Pepper” Dehner, M.D., is a world-renowned pathologist at Washington University in St. Louis and was the first to characterize PPB in 1988.

Anne Harris, M.P.H., C.C.R.P., is a Clinical Research Specialist with the International PPB/DICER1 Registry and International Ovarian and Testicular Stromal Tumor Registry.

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How can I join?

All individuals with PPB or related tumors and conditions and their family members are encouraged to participate.

Phone: 1-800-518-8474 to speak with a member of our research team