What do you mean 'so what'? Maybe you don't read the news...
The whole area of immune therapy for cancer is huge. There are stories in the media and scientific studies on this very regularly.
http://www.theguardian.com/science/...vaccines-show-early-signs-of-promise-in-trial
Regeneus have a personalised vaccine that is being used in vet animals and in trials. I hope it will be used in a human trial soon.
