New York City ? Scientists in Oregon say they’ve reached the long-sought goal of cloning monkey embryos and extracting stem cells from them, a potentially major step toward doing the same thing in people.

The research has not been published yet or confirmed by other scientists. But if true, it offers fresh hope in field that has been marked by frustration and even fraud. The claim of a similar breakthrough with human embryos by a South Korean scientist in 2004 turned out to be false.

The hope is that one day, such a procedure could be used to create transplant tissue that’s genetically matched to an ailing patient. Because stem cells can form all types of tissue, the approach might one day help treat conditions like diabetes and spinal cord injury without fear of rejection by the patient’s body.