Skip to Main Content
An official website of the United States government

Study Team Members

Principal Investigator

Douglas Stewart, M.D.

Dr. Stewart is 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.

Margarita Aryavand is a 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.

Dr. McMaster is a 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.

Dr. Best is 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.

Dr. Kim is a 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.

Dr. Vasta is 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.

As program manager, Cecilia Higgs 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.

Laura is a registered nurse who supports cancer genetics research.

Ann Carr, M.S., C.G.C.

Ann Carr 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.

Stephanie 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.

Dr. Schultz 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.

Dr. Hill 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.

Dr. Messinger is a pediatric oncologist at Children’s Minnesota with many years of experience treating children with PPB.

Louis “Pepper” Dehner, M.D.

Dr. Dehner 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.

Anne is a Clinical Research Specialist with the International PPB/DICER1 Registry and International Ovarian and Testicular Stromal Tumor Registry.