4251
At necropsy 28 days post - inoculation , F344 rats had no gross lung lesions , even those given the maximum dose of 1 . 4 X 10 ( 9 ) colony - forming units of M . pulmonis .
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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