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: To examine the role of the kinin B2 receptor in cisplatin - induced acute kidney injury , kinin B2 receptor knockout mice were challenged with cisplatin .
### Output Text:
To examine the role of the kinin B2 receptor in <span class="chemical">cisplatin</span> - induced acute kidney injury , kinin B2 receptor knockout mice were challenged with <span class="chemical">cisplatin</span> . 