In the sentence extracted from biomedical literature, identify all the chemical entities. The required answer format is the same sentence with HTML <span> tags to mark up specific entities. 
### Entity Markup Guides:
Use <span class="chemical"> to denote a chemical.

### Input Text: RESULTS : The number of damaged cardiomyocytes was 9 . 6 - fold ( 95 % CI 4 . 4 - 21 . 0 ) higher in mice treated with DOX alone than that in animals of the control group .
### Output Text:
RESULTS : The number of damaged cardiomyocytes was 9 . 6 - fold ( 95 % CI 4 . 4 - 21 . 0 ) higher in mice treated with <span class="chemical">DOX</span> alone than that in animals of the control group . 