I believe we all have a few of these mutated cells in our body from the day we are born to the day we move on even if they don’t kill us. This is not based on scientific research just a scientific hypothesis that says our bodies keep the enemy (Cancer Cells) at bay unless the immune systems suddenly has a shock to the system through some type of flu/virus, lack of vitamin intake/sleep or the DNA code being altered from within. This isn’t to say some bodies based on heredity lack the ability to fight such wars for survival and succumb to Cancer penetration in the body it’s just that many others have had this life changing event occur from within. With this theory if we to build a better immune treatment from within the Cancer Cells that do already exist along side us would never take over. Just a hypothesis that will have to be determined by the scientist in the field.