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: This protective effect did not depend on the time interval between monoHER and DOX administration ( P = 0 . 345 ) .
### Output Text:
This protective effect did not depend on the time interval between <span class="chemical">monoHER</span> and <span class="chemical">DOX</span> administration ( P = 0 . 345 ) . 