Definition of a human embryonic stem cell has been broadened by the U.S. Government. Dr. Lana Skirboll, Director of the Office of Science Policy of the National Institutes of Health, said that, this is a technical change and would be posted in the federal register for comment.
Human embryonic stem cells are the body's master cells. They are taken from the initial stage of embryos when they are just a ball of cells. According to the current definition, embryonic stem cells are the cells taken from the inner layer of a blastocyst, a days-old hollow ball of cells.  
"We are making what I think is a relatively small technical change to the definition of human embryonic stem cells. This changes none of the ethical requirements in the guidelines”, said Skirboll in a telephonic interview.
Some constraints on the federal funding of human embryonic stem cell research were lifted by the U.S. President Barack Obama.
"It would have been a disaster to exclude these valuable human embryonic stem cell lines from consideration for federal funding, especially since the leftover embryos used to generate them meet all the NIH requirements”, said Dr. Robert Lanza of Massachusetts-based Advanced Cell Technology.
Some people oppose the research that involves human embryos.