The breakthrough wasn't a simple affair. To pinpoint the human skeletal stem cell, the scientists couldn't just use the tricks they'd used to isolate the equivalent in mice. They had to compare the mouse's gene expression profiles with those of several human cell types you'd find on the growing ends of human bone. That let the group find cells with similar proteins as the mouse's skeletal stem cells, helping the team find relevant markers on human cells.

The findings will should help understand the nature of human bone, but Stanford noted that it's ultimately interested in medical uses. You could heal broken bones at a faster pace, repair cartilage or even grow new bones for reconstructive surgery. Conditions like arthritis and osteoporosis might be much less serious, as you could generate unaffected bones and cartilage as necessary. This is only the beginning, so any solutions are likely years away. Still, there could be a day when you don't have to worry as much about serious fractures or the effects of aging.