Page 4 - Kids and Cancer

Chapter 1
Chapter 1
Chapter 1

What Is Cancer?

ne bad cell is all it takes to set the process of cancer in
motion. That single errant cell divides, multiplies, and
continues to grow uncontrollably until it becomes a
malignant mass of cells invading the body. The very defi nition of
cancer is the uncontrolled growth of cells.

Cells and Cancer

The human body is made up of an estimated 37.2 trillion cells.
Cells are the basic units of all living things. Each cell is a tiny, com-
plex factory that produces the proteins that do the work of the
body. Each cell in the body has its own specifi c function. Cells in
the pancreas, for example, produce the insulin that is necessary
for cells to use sugar for energy. Red blood cells carry oxygen to
the body’s cells. In every organ in the body, billions of cells work
together and perform their specifi c functions as part of an ele-
gantly organized system. When necessary to maintain organ and
tissue health and growth, cells divide in a process called mitosis.
The cell divides into two identical cells, and these daughter cells
can divide again to make four, then eight, then sixteen cells, and
so on. The process of cell division, however, is highly regulated by
chemical signals within the cells. Each cell knows when to grow

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