Our Staff


Jeff Shrager

Chief Technical Officer

As an undergraduate studying Computer Science at UPenn, Jeff developed the first intelligent software agents (what we now call “wizards”). At CMU, studying with Herb Simon and Al Newell, he became interested in scientific reasoning and discovery, and has since been working on intelligent agents that help scientists in their wide-ranging activities. For the past two decades he’s been doing this in molecular micro-biology and in cancer. Jeff co-founded two mildly successful startups in drug discovery robotics and computational oncology. As Cancer Commons CTO, Jeff leads the organization’s exploratory initiatives.


kevin-knopfKevin Knopf

Medical Director

Kevin Knopf MD, MPH is a Health Economist and Health Services researcher as well as a practicing oncologist and site lead for oncology for Sutter Health in San Francisco. His research focuses on large scale data analytics (“big data”), patterns and quality of care in oncology, health disparities in cancer screening, diagnosis, and treatment, and cost-effectiveness in cancer care. He started his research career in the Health Economics and Outcomes Research Branch at the NCI involved with the patterns of care studies, SEER-Medicare database, and the Prostate Cancer Outcomes Study. He is an editor at Value Based Cancer Care and the Journal of Community Oncology.

He is also Vice President of the nonprofit Rooms that Rock 4 Chemo. He has clinical faculty positions at Dartmouth Medical School and the University of California, San Francisco School of Medicine; and was formerly adjunct faculty at the Johns Hopkins Oncology Center. He has been a co-investigator on numerous clinical trials and is former director of clinical research at the Annapolis Oncology Center. Dr. Knopf received an undergraduate degree in mechanical engineering from the Massachusetts Institute of Technology and his medical degree from the University of California, San Francisco School of Medicine. He completed his clinical training at Northwestern Medical School, the Memorial Sloan Kettering Cancer Center, and the National Cancer Institute. He obtained a MPH in Epidemiology and Statistics at the Johns Hopkins School of Public Health.



Emma Shtivelman

Chief Scientist

Emma Shtivelman is a molecular and cell biologist with extensive experience in cancer biology. She has in-depth understanding of cancer signal transduction and metabolism, cancer models in vitro and in vivo, target and drug discovery and validation, assay development, and preclinical research. She has technical expertise in numerous modern methodologies employed to understand the molecular basis of human malignancies and advance preclinical and clinical research.

Emma received her PhD in molecular biology from the Weizmann Institute of Science where she identified the fused transcript between two cellular genes, BCR and ABL in chronic myelogenous leukemia (CML), the first demonstration of an oncogenic gene product derived from a chromosomal translocation. As a postdoctoral fellow at the University of California, San Francisco (UCSF), she characterized the molecular consequences of chromosomal translocations in Burkitt lymphoma and identified gene products relevant to the pathogenesis of neuroblastoma.  She worked at Systemix on establishing a novel SCID-hu metastasis model to enable the in vivo analysis of human tumor metastasis. She continued her research activity at the UCSF Cancer Center analyzing deregulation of signal transduction pathways in human cancer and the molecular underpinnings of metastatic progression. Before joining Cancer Commons, Emma worked at BioNovo, Inc., researching new drugs that selectively disrupt metabolism of breast and pancreatic cancers by targeting their metabolic preferences.



Vaishali Walia

Director of Engineering

As Director of Engineering at Cancer Commons, Vaishali is focused on developing the technology platform that powers Cancer Commons’ services and is excited about the opportunity to transform cancer care. Vaishali has specialized in leading global engineering teams, taking products from concept to launch in telecom, payment processing, and automotive industries.

Prior to joining Cancer Commons, Vaishali co-founded two successful startups. At her first startup, Konark, she led the development of electronic bonding products for supply chain automation between competitive and incumbent local exchange carriers. Konark was acquired by DSET Corporation, where Vaishali continued heading engineering for the ezCare line of products. At her second startup, Telanox, she developed an Order Management System for competitive carriers along with a suite of integrated provisioning services. This was followed by Telanox’s second initiative in network performance management products, where she set up and ran an overseas subsidiary in addition to heading R&D, engineering and support organizations. Prior to Telanox, Vaishali managed the engineering team at NetDeposit for development of an enterprise check processing system using distributed remote image capture and electronic clearing that revolutionized the way we bank. Vaishali has been an early adopter of web technologies and began her career by spearheading the effort to put automotive part and labour catalog services online at Triad Systems.

Vaishali has an M.S. in Computer Science from the University of Florida, Gainesville.



Masako Yokota

Director of Administration, Executive Assistant to the Founder & Chairman

As Director of Administration and Executive Assistant to Marty Tenenbaum, Masako works behind the scenes, taking care of critical logistics so that Marty can focus on the bigger vision of Cancer Commons and make it a reality.

Prior to joining Cancer Commons, Masako worked in a variety of sectors, including venture capital, real estate, academia, and technology. With 10+ years of experience supporting C-level executives, she aspires to apply all her knowledge and assist the team to achieve the best resolutions. As a non-smoker lung cancer survivor, she is committed to increasing awareness of the stigma surrounding this particular form of cancer.

Masako, a native of Japan, has a B.A. in music and teaches young children piano and voice. She also volunteers at local schools as a guest conductor for musical productions.



Piers Mahon

Director, Global Alliances

In his role as the Director of Global Alliances, Piers helps link European cancer information and patient advocacy groups to the commons for broader global patient benefit. A particular focus within that is the creation of stratified, consented, real world outcome registries in Europe’s national healthcare systems to create world class research tools for precision medicine development.

Previously, Piers was with management consultants Bain & Company for 14 years, focusing on drug development, innovation strategy and healthcare private equity. There he worked on a number of precision medicine launches, including leading the global launch plan for ponatinb (now Inclusig®) in Chronic Myeloid Leukaemia with ARIAD pharmaceuticals in Boston. He has had a long interest in not-for-profit and social enterprise, with clients ranging from the Wellcome Trust (the 2nd largest biomedical research foundation globally) to smaller venture-philanthropy organizations such as The Impetus Trust (now Impetus-PEF). Piers combines his role at Cancer Commons with independent consulting in precision medicine development and deployment.

Piers has a PhD from Cambridge University in proteomics, where he also completed his undergraduate degree in Natural Sciences. He is based in London.



Sarah Stanley


Sarah Stanley is Editor at Cancer Commons, where she prepares actionable, patient-friendly content for people dealing with cancer. Her writing has previously appeared in Discover magazine and in Popular Science. She has also written for PLOS, the American Geophysical Union, the Marine Biological Laboratory in Woods Hole, Massachusetts, and for the European Molecular Biology Laboratory in Heidelberg, Germany. Sarah studied microbiology at the University of California, Santa Barbara, and writes music under the name Focusbird.



Martha Dehnow

Accounting Manager

As Accounting Manager, Martha Dehnow handles all aspects of finance and accounting for Cancer Commons. Her specialty is helping startups and small companies grow to their fullest potential by allowing founders to focus on their core business. Prior to Cancer Commons, Martha worked for CommerceNet and BDNA Corporation. She has also worked for early stage startups, such as EIT and Veo Systems, which were later acquired by VeriFone, Hewlett-Packard, and CommerceOne.



Stacey Tinianov (Director of Patient Services)
William T. Wong, PhD (Executive Director)
Sarah Greene (Executive Director, now at Rapid Science)
Ash Shairzay (Design Director)
Alam Kasenally (Engineering Director)