A breast cancer cell line known as MCF-7 is used by researchers around the world. 聽The name comes from the Michigan Cancer Foundation where the cell line was first established in 1973 after isolating the cells from Sister Catherine Frances, a Catholic nun. 聽Aside from use in breast cancer research, the cell line has also proven to be valuable in testing for estrogenic activity. 聽Cells can be exposed to various chemicals and their rate of multiplication assessed. 聽Compounds with estrogenic activity trigger more rapid multiplication, the extent of which can be monitored by isolating and quantifying the amount of DNA in the newly formed cells.