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 : Patients with tamoxifen - induced liver dysfunction may be at increased risk for granulosa cell tumors because of alterations in tamoxifen metabolism .
### Output Text:
CONCLUSION : Patients with <span class="chemical">tamoxifen</span> - induced liver dysfunction may be at increased risk for granulosa cell tumors because of alterations in <span class="chemical">tamoxifen</span> metabolism . 