1.   Many questions about fatal familial insomnia remain.

2.   Others, like Creutzfeldt-Jakob disease and fatal familial insomnia, are exceedingly rare diseases of humans.

3.   Their hunch that mad cow disease and fatal familial insomnia were somehow connected would turn out to be right.

4.   That confirms the idea that the disease, called fatal familial insomnia, belongs to a small group of neurological disorders caused by an abnormal protein called a prion.