Explanation:
I would turn the sentence around

9 May 2012 – Your immune system is a collection of organs, special cells, and substances that ... to serve their own purposes, and they can hurt you in the process. ... But the immune system is much better at recognizing and attacking germs than cancer cells. ... The immune system may not see the cancer cells as foreign ...

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Note added at 4 hrs (2012-06-02 17:34:13 GMT)
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or

identifies

if you prefer

Flies In Space - Immune System
quest.nasa.gov/projects/flies/immune.html
The immune system works by identifying foreign invaders in the body- this is called recognizing “self from non-self”. Special immune cells in the body are able to ...

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Note added at 4 hrs (2012-06-02 17:36:16 GMT)
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or

whereby the immune system sees/identifies non-self cells

How do your cells recognise invaders?
www.sciencemuseum.org.uk › ... › Your body › What do your cells do?
Any invaders, such as bacteria and viruses - 'non-self' - are immediately detected by your immune system and destroyed. Cell recognition is also vital for ...


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Note added at 4 hrs (2012-06-02 17:42:14 GMT)
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Cells of the Immune System
pathmicro.med.sc.edu/bowers/immune%20cells.htm12 Jul 2010 – CELLS INVOLVED IN IMMUNE RESPONSES AND ANTIGEN RECOGNITION ... to protect the host from pathogens and other foreign substances. Self/non-self discrimination is one of the hallmarks of the immune system.

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Note added at 8 days (2012-06-11 09:43:02 GMT) Post-grading
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Hi again

Your sentence implies that this is attibutable to Milstein, or does this sentence just appear in a series of acknowledgements of those involved in this area of research and discover?

I ask this because of...

http://www.nndb.com/people/697/000131304/

Born in Venezuela, raised in France, and educated in America, pathologist and**** immunologist Baruj Benacerraf ****discovered the genes that regulate the body's immune responses, and showed how these genes are involved in autoimmune diseases (in which the immune system mistakenly attacks instead of defends). In 1980 he received the Nobel Prize for Medicine or Physiology, for "discovery of the Major histocompatibility complex genes which encode cell surface molecules important for the immune system's distinction between self and non-self."


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Note added at 8 days (2012-06-11 09:45:06 GMT) Post-grading
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ooh er, kindly ignore that question, have just seen this too:

www.history.qmul.ac.uk/research/modbiomed/.../wit.../44823....
File Format: PDF/Adobe Acrobat - Quick View
by E OPIATES - 1997 - Cited by 1 - Related articles
SELF AND NON-SELF: A HISTORY OF AUTOIMMUNITY ... Monoclonal Antibodies: Dr Georges Köhler (1946–95), Sir Christopher Booth, Dr César Milstein ..... participating included the two authors of the Nature article, Dr César Milstein and ...