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: With paclitaxel doses of 200 mg / m2 and higher , granulocyte colony - stimulating factor 5 micrograms / kg / d is given ( days 4 through 12 ) .
### Output Text:
With <span class="chemical">paclitaxel</span> doses of 200 mg / m2 and higher , granulocyte colony - stimulating factor 5 micrograms / kg / d is given ( days 4 through 12 ) . 