1994 - Niels Kaj Jerne died.

Jerne was a Danish immunologist who shares the 1984 Nobel Prize in Medicine with Georges Köhler and César Milstein for their work concerning the immune system and discovery of monoclonal antibodies. He developed theories as to how the body produces the many different antibodies to protect the body from infection, the thymus is used to distinguish between its own components and those that are foreign and the immune system can self-regulate to turn itself on or off as needed.