In this volume of Reviews of Physiology, Biochemistry and Pharmacology there a contributions by M.D. Swope, E. Lolis, F.Hofmann, L. Lacinova, N. Klugbauer, M. Hermann, P. Berger, S.S. Shen, J.S. Kim, M.E. Weksler, M. Hirsch-Kauffmann and M. Schweiger. TOC:M.D. Swope and E. Lolis: Macrophage migration inhibitory factor: Cytokine, hormone, or enzyme?- F. Hofmann, L. Lacinova, and N. Klugbauer: Voltage-dependent calcium channels: From structure to function.- Special contributions to the topic aging: M. Hermann and P. Berger: Aging of the male endocrine system.- S.S. Shen, J.S. Kim and M.E. Weksler: Effect of age on thymic development, T cell immunity, and helper T cell function.- M. Hirsch-Kauffmann and M. Schweiger: Aging and chromosomal instability.