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: CONCLUSION : These data support a model wherein a p53 - dependent cardioprotective pathway , mediated via STAT3 activation , mitigates DOX - induced myocardial stress during drug delivery .
### Output Text:
CONCLUSION : These data support a model wherein a p53 - dependent cardioprotective pathway , mediated via STAT3 activation , mitigates <span class="chemical">DOX</span> - induced myocardial stress during drug delivery . 