The concept of immunological surveillance.

The following year, he wrote Immunological Surveillance, which expounded his established opinion that mammals could immunise themselves through their ability to detect foreign patterns in the body.

After 1957 all new staff and students at the Institute worked on immunological problems; Burnet was involved in work relating to autoimmune diseases and the graft-versus-host reaction, and increasingly in theoretical studies of immunology, immunological surveillance and cancer.