"A bond made up of life settlements would ideally have policies from people with a range of diseases — leukemia, lung cancer, heart disease, breast cancer, diabetes, Alzheimer’s. That is because if too many people with leukemia are in the securitization portfolio, and a cure is developed, the value of the bond would plummet."
It's like something the Hollywood style corporate bad buy caricature would do.
http://www.nytimes.com/2009/09/06/business/06insurance.html