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Unformatted text preview: th. Although cells can die as a
result of unpredictable traumatic events, such as exposure to toxic chemicals, most cell deaths in multicellular organisms occur by a normal physiological process of programmed cell death, which plays a key role both in
embryonic development and in adult tissues.
In adult organisms, cell death must be balanced by cell renewal, and
most tissues contain stem cells that are able to replace cells that have been
lost. Abnormalities of cell death are associated with a wide variety of illnesses, including cancer, autoimmune disease, and neurodegenerative
disorders, such as Parkinson’s and Alzheimer’s disease. Conversely, the
ability of stem cells to proliferate and differentiate into a wide variety of
cell types has generated enormous interest in the possible use of these
cells, particularly embryonic stem cells, to replace damaged tissues. The
mechanisms and regulation of cell death and cell renewal have therefore
become areas of research at the forefront of biology and...
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