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: Apart from this cytostatic effect , temsirolimus had an antiangiogenic effect with decrease of tumor microvessel density and of VEGF expression .
### Output Text:
Apart from this cytostatic effect , <span class="chemical">temsirolimus</span> had an antiangiogenic effect with decrease of tumor microvessel density and of VEGF expression . 