Expert Panel Concludes 'STAP Cells' Were Created By Mixing In Embryonic Cells

TOKYO, JAPAN - DECEMBER 26: Riken national institute executives Maki Kawai (R) and Mutsuhiro Arinobu attend a press conference on December 26, 2014 in Tokyo, Japan. The breakthrough type of pluripotent cells known as STAP claimed to have been created by a group of scandal-hit scientists was most likely produced by introducing embryonic stem (ES) cells into the production process, an investigative panel concluded. The outside panel said it has yet to determine whether the mixing was deliberately done and who was responsible. However, it said former Riken institute researcher Haruko Obokata, at the center of the controversy, fabricated two additional pieces of data in papers carried in the British science journal Nature in January. (Photo by The Asahi Shimbun via Getty Images)