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: We think that even these lower dosages of cyclosporine can cause chronic nephrotoxicity and that further modification of the immunosuppressive regimen is required to completely abolish this toxic side effect .
### Output Text:
We think that even these lower dosages of <span class="chemical">cyclosporine</span> can cause chronic nephrotoxicity and that further modification of the immunosuppressive regimen is required to completely abolish this toxic side effect . 