Medical researchers have discovered what may be the key to controlling the growth of cancer cells, in a process that looks promising in terms of not only halting the growth of tumors, but also in reversing that growth.

Researchers at the Mayo Clinic in Florida have found that cell growth is regulated by genetic structures called microRNA–basically, molecular processors that tell a cell when and when not to reproduce. This miRNA triggers the production of a protein called PLEKHA7, of which tells the cell to cease dividing when division is no longer necessary.

Cancer is, quite infamously, the uncontrolled growth of a mass of what would have been otherwise ordinary cells within the body. The researchers removed the microRNA from test cells, of which halted the production of PLEKHA7, of which triggered uncontrolled division in the cells. Then, when miRNA was reintroduced to the cells, they found that cell division stopped, indicating that the introduction of miRNA into cancer patients might be the key to halting tumor growth.