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: Proteinuria is an expected complication in transplant patients treated with mammalian target of rapamycin inhibitors ( mTOR - i ) .
### Output Text:
Proteinuria is an expected complication in transplant patients treated with mammalian target of <span class="chemical">rapamycin</span> inhibitors ( mTOR - i ) . 