Dr. Robert Lanza, chief scientist at the stem cell company Advanced Cell Technology, said “[these new stem cells] can clearly generate a broad range of important cell types, but they may not do as many tricks as embryonic stem cells.”
Dr. George Daley, a Harvard University stem cell researcher, said “While the [new stem cells] are fascinating subjects of study in their own right, they are not a substitute for human embryonic stem cells, which allow scientists to address a host of other interesting questions in early human development.”
Dr. Larry Goldstein, a professor of cellular and molecular medicine at UC San Diego, said the absence of tumors in the new stem cells might signal a limitation. “It makes me wonder how pluripotent they are.” Though the cells might prove useful in some circumstances, Goldstein said, they aren’t a substitute for embryonic stem cells. “They built a screwdriver here, but I need a wrench.”
Dr. Anthony Atala, director of the Institute for Regenerative Medicine at Wake Forest University School of Medicine and the leader of the group of scientists that discovered the amniotic-fluid stem cells, commented that the new stem cells would not replace embryonic stem cells.