"Host factors" - evolution of concepts of individual sensitivity and susceptibility

The detection of a rapidly increasing number of genetic polymorphisms in xe nogen-metabolizing enzymes, of hereditary as well as acquired individual di fferences in DNA repair, and of the close associations between central nerv ous structures, the endocrine, and the immune system provides a challenge t o develop an evidence-based, comprehensive model of susceptibility. Reviewi ng the evolution of respective approaches from 400 B.C. until today, this a rticle proposes a conceptional framework that integrates the diverse, and s ometimes puzzling contributions from all different fields of life science.