Since the discovery of the bone morphogenetic proteins (BMPs) more than 15 years ago, there has been an unpredicted explosion of both basic scientific discoveries and clinical reports on their use from institutions all over the world. The potent effica­ cy of BMPs in almost all crucial developmental events as well as during regenera­ tion of various organs such as bone, kidney, brain, liver, heart etc. , has positioned BMPs at the center of scientific interest. Many of these aspects are covered in this new PIR volume. Their role in development, biology, signal transduction, kidney regeneration, eNS functions, craniofacial skeleton reconstruction, joint and carti­ lage repair, long bone non-unions and acute fractures, and spinal fusion is reviewed by experts in the field. For the first time, the role of BMPs in carcinogenesis has been reviewed to provide a rationale for applying their biology in patients with bone tumors. The optimism resulting from safe and successful treatment with BMPs for various skeletal malformations of more than 10,000 patients worldwide has opened new avenues for exploring other indications for their use. The next big challenge for bringing BMPs to the benefit ofmankind is in regenerating articular cartilage defects and rescuing patients with acute and chronic renal failure. The volume editors thank all authors for the rapid preparation of their chapters in order that the book remains up-to-date for readers with specific interest in the field of regenerative medicine. The important contribution of Mrs. Morana and Mr.