21.   From this colony, the researchers extracted cells that were following a linage that would lead to mature endothelial cells.

22.   Looking for PIN is much more difficult, because it requires sticking a needle into the prostate to extract cells for examination.

23.   The Clinton administration decided to allow federal money to pay for stem cell projects as long as the cells were extracted by researchers not receiving federal funds.

24.   The use of embryonic stem cells is controversial because extracting the cells kills a living human embryo.

25.   To get the DNA, scientists extracted cells from a molar tooth of Cheddar Man.