This essay chronicles the major theoretical and experimental contributions made by Charles A. Janeway, Jr. (1943-2003), Howard Hughes Medical Institute investigator and Yale Professor of Immunobiology, who established the fundamental role of the innate immune system in the induction of the adaptive arm.
Keywords: B7 molecules; Janeway; Medzhitov; Toll-like receptors; co-stimulation; induction; infectious non-self; non-infectious self; pathogen-associated molecular patterns; pattern recognition receptor; signal 1; signal 2; two-signal hypothesis.