Interferons were among the first cytokines to be studied clinically in recombinant form in the 1980s, beginning a new era of pharmacotherapy in internal medicine. Interferons were soon employed in the treatment of tumors and it was shown that those hematopoietic neoplasias which had been difficult to treat with chemotherapy responded well to interferon treatment. In the present volume, renowned international authors update the importance of interferons in various fields of internal medicine, dermatology, and urology. The book also contains a general introduction into the classification, structure, and mode of action of interferons. Further chapters discuss the range of side effects of these substances and point out possible focuses of further clinical interferon research.