“Bright-eyed, bouncy, and very friendly” is how the BBC described the world’s first three mule clones—Idaho Gem (pictured), Utah Pioneer, and Idaho Star—five years ago. The man who helped create them, Colorado State University veterinary medicine and biomedical sciences professor Gordon Woods, passed away late last week. In 2003, Woods, Dirk Vanderwall of the University of Idaho, and Ken White of Utah State University brought Idaho Gem to life as part of a larger project intended to gauge why horses have a significantly lower rate of cancer than humans. “Gordon’s hypothesis was that excessive intracellular calcium in human cells could be an underlying factor in age-onset diseases,” Vanderwall tells The Associated Press. In recent years, leaders in thoroughbred horse racing and equine health donated $1.14 million to Woods’ laboratory to support his disease research, according to a CSU press release from earlier this year. Woods died at the Medical Center of the Rockies in Loveland, according to a CSU spokeswoman. His cause of death and age were not immediately available. As for Idaho Gem, he became successful on the mule-racing circuit in Nevada and California.