Thank you David for your reply. It is a difficult question, but I wondered what some of the people here in the forum thought. My understanding from a lay persons view is that it kills all the good and bad cells in the body not really sure of the details either. When you think of it... what cells?? I also believe it works with the radiation, killing the cancerous cells and takes good cells with it. I would like to know what other people think on this subject. Thank you again. Carol...