These cells were also created using mouse cells, starting with mouse skin cells, and the comparison between what you get from a mouse cell that's transformed this way and an embryonic stem cell, they look to be very similar.

NPR: Scientists Create Embryonic Stem Cells from Skin

First came the remarkable work of Shinya Yamanaka at Kyoto University, who showed it was possible, by activating just four genes, to take a mature cell (he used a bit of skin but other cells would work) and turn it into the equivalent of an embryonic stem cell with the potential to become any other cell in the body of mouse or human.

FORBES: Cells Get a Makeover, Cancer Follows: A Path to New Therapies (and a Warning to Stem Cell Alchemists)