In memory of the immunologist Jan Klein

After a short illness, prof. Jan Klein died on 7 May 2023. The Czech-American immunologist was director of the Max Planck Institute, a teacher at Pennsylvania State University and one of the founders of modern immunogenetics. In 2018 he received the Neuron Award for contribution to world science in the field of biology. Honour to his memory.

The biologist Jan Klein was often described as a successor to the famous geneticist J. G. Mendel — he made several fundamental discoveries concerning what is called the major histocompatibility complex (MHC), which plays a fundamental role in the immune system. It controls the production of antibodies against bacteria and viruses, which is the good thing about it, but unfortunately it also significantly complicates organ transplants. Antibodies do not attack the body's own cells but recognise foreign intruders. Jan Klein focused on investigating how this mechanism works. His genetic characterisation of the organism's immune response is a discovery of world significance.