TOKYO (AP) — The Japanese scientist accused of falsifying data in a widely heralded stem-cell research paper said Wednesday the results are valid despite mistakes in their presentation.

Haruko Obokata, 30, struggled to maintain her composure during a televised news conference packed with hundreds of reporters, but insisted she did not tamper with the data to fabricate results. She said she did not agree with retracting the research that appeared in the scientific journal Nature.