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: The novel immunosuppressive ( IS ) drug sirolmus ( Srl ) lacks nephrotoxic effects ; however , proteinuria associated with Srl has been reported following renal transplantation .
### Output Text:
The novel immunosuppressive ( IS ) drug <span class="chemical">sirolmus</span> ( <span class="chemical">Srl</span> ) lacks nephrotoxic effects ; however , proteinuria associated with <span class="chemical">Srl</span> has been reported following renal transplantation . 