I originally started looking into CoQ10 to help protect my wife's heart from doxorubicin toxicity. Go to any knowledgeable health practitioner (ND, nutritionist, alternative doctor) and they will insist that you take CoQ10 to protect against doxorubicin toxicity. My wife, being a cell biologist did some research by Kenneth Conklin and thought that it made sense.
That said, I am now seeing small studies and anecdotes claiming that "high-dose" CoQ10 can even reverse cancer. There is also evidence that CoQ10 levels are lower in cancer patients.