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: Cytostatic and anti - angiogenic effects of temsirolimus in refractory mantle cell lymphoma .
### Output Text:
Cytostatic and anti - angiogenic effects of <span class="chemical">temsirolimus</span> in refractory mantle cell lymphoma . 