21.   As the programming instructions of the human cell, the genes provide all the information needed to develop, operate and maintain the human organism.

22.   At a Genetic Therapy laboratory in Gaithersburg, Md., Susan Thomas lifted human cells from a tank of liquid nitrogen.

23.   Bacteria from spores generate in the lungs and produce several toxins that attack human cells.

24.   Biologists can now hope to understand many diseases at the level of the human cell by comparing gene expression in normal and diseased tissue.

25.   Biologics, which historically included blood products and vaccines, are today considered any product that is composed of a living organism, such as human cells or tissue.

26.   Biologists at Geron, of Menlo Park, Calif. have succeeded in making human embryonic cells develop into heart muscle cells.

27.   Biologists recently got a taste of immortality when they found that human cells kept in culture would grow and divide indefinitely if their telomeres were artificially lengthened.

28.   A cow egg stripped of its nucleus would be fused with a human cell to create a nonviable cloned embryo, from which embryonic stem cells would be taken.

29.   A new test that can detect several kinds of cancerous human cells was reported Monday by scientists from the Johns Hopkins School of Medicine in Baltimore.

30.   A Japanese researcher weakened the virus by growing it in both human fetal cells and animal cells.