This was very sad news.
I was a postdoc in Jeff's lab from 1985 to 1990 and had the opportunity to appreciate his sharp view of science and kind attitude to everybody in  the lab. He was never getting impatient to someone else’s mistakes, and was very helpful all the time.

I know little about the battle Rob Kay mentions. Jeff's last statement to me announced a stop in communication, due to his will to be remembered as a healthy and smart person, and I haven't heard from him ever since. Respecting his will I never tried to get in touch again, and it was kind of painful knowing to have to wait for this as the next most probable news.
We all die a little when someone we loved dies. Of the two people who really made my very short scientific life enjoyable he was one, and both had Williams in their surnames. He is now the last signpost I can remember, and he will never be forgotten.

Adriano