János Hugo Bruno "Hans" Selye CC (/ˈsɛljeɪ/; Hungarian: Selye János; January 26, 1907 – October 16, 1982) was a pioneering Hungarian-Canadian endocrinologist who conducted important scientific work on the hypothetical non-specific response of an organism to stressors. Although he did not recognize all of the many aspects of glucocorticoids, Selye was aware of their role in the stress response. Charlotte Gersonconsiders him the first to demonstrate the existence of biological stress.