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 : Raloxifene was associated with an increased risk for venous thromboembolism , but there was no increased risk for cataracts , gallbladder disease , endometrial hyperplasia , or endometrial cancer .
### Output Text:
CONCLUSION : <span class="chemical">Raloxifene</span> was associated with an increased risk for venous thromboembolism , but there was no increased risk for cataracts , gallbladder disease , endometrial hyperplasia , or endometrial cancer . 