21.   Ultimately, Krauss hopes to develop a biochemical test that would measure the substances produced by genes that trigger heart disease.

22.   While homeobox genes produce transcription factors, which work within the cell nucleus, BMP molecules are used to send signals from cell to cell.

23.   While homeobox genes produce transcription factors, which work within the cell nucleus, B.M.P. mole- cules are used to send signals from cell to cell.

24.   With the mapping of the human genome, scientists have sought additional computing power to help decipher the rules by which the proteins produced by genes assume their shapes.

25.   And these genes produce distinctive markings on modern human skulls.

26.   But scientists might someday develop a pill to block the protein the gene produces, which would keep patients from accumulating more iron, Andrews said.

27.   In a healthy cell, the gene produces a protein that helps signal cells to grow normally and multiply.

28.   Once inside the cells, the genes produce the two proteins.

29.   The Beacon gene produces a protein that stimulates the appetite.

30.   The gene produces enzymes called alcohol dehydrogenase that break down alcohol.