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'''White blood cells''' are a component of [[blood]]. As part of the body's [[immune system]], their function is to protect the body from disease and infection. White blood cells come in several varieties, each with a different role to play in neutralising harmful foreign substances. White blood cells, like all [[blood cells]], are produced in the [[bone]] marrow.

'''White blood cells''' are a component of [[blood]]. As part of the body's [[immune system]], their function is to protect the body from disease and infection. White blood cells come in several varieties, each with a different role to play in neutralizing harmful foreign substances. White blood cells, like all [[blood cells]], are produced in the [[bone]] marrow.

They are also known as leukocytes.

They are also known as leukocytes. There are five main types of leukocytes, and these types are produced from immature cells in the [[lymphatic system]] in response to the body's needs. For example, infection with bacteria will cause more [[macrophage]]s to be produced and fewer NK cells, in response to "alarm signals" called [[chemokine]]s.

==See Also==

==See Also==