A Dear Friend & Colleague 

It is with tremendous sadness that I share the news that my dear friend and colleague, Dr. Ralf Kleef, MD, passed away on Monday, December 6, 2021. The underlying cause of death was COVID-19.  Ralf was only 60 years old.

Dr. Kleef received his medical training in Germany, Austria, England, and then finally as a Postdoctoral Research Fellow in Immunology at Memorial Sloan-Kettering Cancer Center, in New York City. His primary mentor at MSKCC was the incredible Lloyd J. Old, M.D., vice president of Sloan-Kettering Institute. During this time Ralf became a close friend of Helen Coley-Nauts, a distinguished research scientist, and daughter of William B. Coley, MD – the father of Cancer Immunotherapy.  It was Coley who introduced fever therapy for cancer to the modern world. This relationship further inspired Ralf’s focus on hyperthermia and fever therapy in cancer treatment.

Dr. Kleef was one of my primary mentors when I first entered into the field of hyperthermia and immunotherapy. I twice spent a week with him at his world-renowned klinik in Vienna, Austria. He selflessly shared his knowledge and wisdom with me, as with many other colleagues, with the intention of helping more patients. I also had the pleasure of spending time with Ralf at our annual international hyperthermia conferences. We shared many patients over the years, as I referred to him and vice versa. A couple of years ago when I published the Textbook, Ralf offered to provide an endorsement, one that will forever remain on the back cover of the first edition.

Ralf, you will be dearly missed. You have left a huge hole in the field of integrative cancer care. Your loss will be felt by both patients and doctors alike. You have left us all way too early my friend. May you rest in peace Ralf.

Forever and always,

Gurdev Parmar, ND, FABNO(USA)