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Every Test is Performed and Reported Personally by Dr. Weisenthal  

Dr. Weisenthal found his current laboratory in 1992 after he had worked as a medical oncologist and cancer researcher at the National Cancer Institute, for the Veterans Administration, and at a national cancer testing laboratory company, where he was Founder and Medical Director. 

Larry Weisenthal, M.D.,Ph.D. is a medical doctor. He is board certified in Medical Oncology and Internal Medicine and is Clinical Professor of Medicine, (Hematology/Oncology), University of California Irvine School of Medicine.  Dr. Weisenthal received his post-doctoral oncology training at the National Cancer Institute, where he was Clinical Associate, cancer researcher, and Lt. Commander in the U.S. National Health Service.  He also holds a separate Ph.D. degree in pharmacology research.

Dr. Weisenthal is widely regarded to be the world’s leading authority in cytometric profiling.  An early pioneer and sustaining force, Dr. Weisenthal invented the Weisenthal DiSC assay, which experts worldwide have called the “gold standard.” 

He introduced the game-changing principal of measuring cell death in mixed populations of dividing and non-dividing cancer cells.  He did this at a time when the medical reserach establishment was deeply invested, academically and finanicially, in the far less accurate cell profiferation endpoint.  Successive generations of reserachers proved Dr. Weisenthal correct and his method is now the dominant approach worldwide.  

Similarly, he pioneered the use of three dimensional cell "organoids," which more accurately preserve native tumor architecture and function.  He did this at time when the NCI and other investigators were firmly set upon using two dimensional cell culture systems.  Once again, Dr. Weisenthal's method is the one that has withstood the test of time.  

As a recognized leader in the field Dr. Weisenthal is highly sought-after as a speaker at meetings of cancer physicians and researchers throughout the world.  

A Highly Experienced Staff Focusing on One Patient at a Time

Our staff consists of medical technologists and laboratory technicians.  We are dedicated, skilled, and highly experienced at assisting Dr. Weisenthal in performing Precision Functional Cancer Testing for cancer patients.

We work closely together as a team in order to accord each patient a highly-focused, highly-caring, and highly-personalized experience. 

We invest a great deal of time and effort in performing a thorough, accurate, high quality analysis for each patient. 

Our goal is to help one patient at a time.  In this, we spare no effort or expense.  We apply three to five separate testing technologies for each patient and spend hours in sample preparation to achieve the best result.  When it comes to your care there is no such thing as “good enough.” 

Each of us at Weisenthal Cancer Group is closely involved at some level in every patient’s personalized cytometric profiling service.  We are all highly dedicated.  We understand that what happens in our laboratory - and literally in our own hands - is each patient’s very best hope to find the chemotherapy treatment that will extend his or her life.  We take that enormous responsibility very seriously and extremely personally.





Weisenthal Cancer Group is licensed by the United States Department of Health and Human Services and by the State of California.  This approval allows us to perform testing for patients in the United States and throughout the world. 

U.S. CLIA accreditation and California license numbers are show below:


 CLIA License Number: 05D0662326

Hospitals: Please click here to view a copy of our current CLIA Certificate


CA License Number: 203076