(Photo by Jeff Miller/UW-Madison)

Su-Chun Zhang and his team of University of Wisconsin researchers have successfully converted skin cells to nervous system cells directly, the university announced recently.

Skipping the induced pluripotent stem cell (iPSC) stage means the cells can’t become tumors.

“iPSC cells can generate any cell type, which could be a problem for cell-based therapy to repair damage due to disease or injury in the nervous system,” Zhang said in a statement.

The researchers exposed skin cells from humans and monkeys to the Sendai virus, which was killed by warming the culture dishes. After 13 days, the researchers harvested what are called induced neural progenitors, which grow without forming obvious defects or tumors.