SEOUL - Patient-specific stem cells that disgraced South Korean cloning expert Hwang Woo-Suk said he had produced this year do not exist, investigators have concluded, according to a news report Monday. A panel at Seoul National University, which allowed DNA tests to be conducted to verify Hwang's research published in the US journal Science, said there was no evidence to support the existence of tailored stem cells, Yonhap news agency said. "There were no such patient-specific stem cells as in the 2005 paper of Science," it said, without naming its source, while adding the panel had been analyzing the DNA...