"Stress-Inducible Cellular Responses" are essential for survival of cells of all species under adverse conditions. At the molecular level this is ac­ complished by a number of essential proteins all of which are involved in various aspects of cellular homeostasis through protective or adaptive func­ tions. Interestingly, molecules such as heat shock proteins have properties as molecular chaperones and are involved in multiple stages of a protein biogenesis beginning with synthesis and involvement in the subsequent events of folding, translocation, and degradation. Heat shock proteins have a critical role to stabilize folding intermediates and to prevent protein aggregation. In addition, stress-proteins serve as targets for immune re­ sponses in immune homeostasis and during infections. The term Stress Response reflects the rapid growth and breadth of this field which includes the molecular and cellular response to drugs, UV irra­ diation, oxidative stress, and environmental toxins. Radical scavengers such as superoxide dismutases and inducible regulatory proteins of metall­ ic ion status such as ferritin and protein disulfide isomerases are also con­ sidered within the frame of stress proteins and represent a new and growing class of stress responses.