A tribute to Xiangzhong "Jerry" Yang.

With the death of Xiangzhong ‘‘Jerry’’ Yang on February 5, 2009, the scientific community lost a pioneer in livestock breeding, a staunch advocate of the use of cloning technology, a fervent internationalist, and a very courageous man. He will be greatly missed. Jerry Yang was born on July 31, 1959, in rural China in a village some 300 miles south of Beijing, where his parents were farmers. Times were very hard during that year, and he barely survived the famine of 1959–1960. His first step into a different world came when he was awarded a place at Beijing Agricultural College on the basis of exceptional marks in the entrance examination. After graduating in 1982 he gained a scholarship that enabled him to undertake graduate studies in the United States. He elected to study at Cornell University, where he took first an MSc and then in 1990 a PhD in reproductive science. It was here that he did his first research with mammalian embryos. He really began to make his mark in cloning research in Connecticut, where he moved in 1996. Inspired by the birth of Dolly, he worked with Japanese collaborators to produce six cloned calves from a prize bull. A year later, in 1999, Amy, the first clone of an adult farm animal in the United States, was born. A great deal of his subsequent research was to optimize the cloning procedure and show that clones are healthy, can reproduce normally, and are safe to eat. Whereas it had been shown that Dolly had short telomeres, Jerry demonstrated that Amy had telomeres of normal length, as we now know is usually the case. It was around Jerry that in 2000 Connecticut established a Center for Regenerative Biology to focus upon the opportunities that are emerging from cloning and stem