Synopsis This book provides an in-depth coverage of the basic principles on immunology. Emphasis is given on the topics of current interests and an attempt has been made to provide ample information on topics like cytokines, interferon, tumour and transplantation immunology. The book will serve as a major reference-cum-textbook to undergraduate and postgraduate students of zoology, biotechnology and microbio0logy,. This way the book is unique work in the subject.