The first new finding is an obvious onethe mouse experiments worked in human cells. Just because something worked in mice doesn't necessarily mean it will work in people too. So this is a really important finding.
The second important finding has to do with the specific genes each group used. Both groups added four genes to turn a stem cell into an ES cell. But they used a slightly different set of genes.
The Japanese group added OCT3/4, SOX2, KLF4, and c-MYC. The Wisconsin group added OCT4, SOX2, NANOG, and LIN28. This matters because of a side effect seen in the previous mouse study.
The mouse study went farther than the human study in that the researchers added these new ES cells to a mouse embryo. The results were disconcerting. Around 20% of the mice developed cancer from the cells. The researchers hypothesized that the cause was one or more of the genes that were used to create the ES cell.
By using different sets of genes in the human cell study, the researchers showed you don't need the same four genes to create an ES cell. The hope is that the researchers will find a combination of genes that do not cause cancer.
Once the scientists find a set of genes that don't cause cancer, this research should blow the stem cell field wide open. We still don't know if ES cells will work to actually cure disease. But ethical ES cells should open the spigot of federal funds so American scientists can finally research this subject to its full extent. Then we'll see if ES cells can really live up to their hype. Or if we need to pursue other ways to cure these illnesses.