11971
PATIENTS AND METHODS : Between June 1991 and December 1996 , we administered the nucleoside analog 2 - chlorodeoxyadenosine ( 2 - CDA ) to 73 children with primary AML and 20 children with secondary AML or myelodysplastic syndrome ( MDS ) .
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Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: GENE 
Text: {0} 
Answer:
 None