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: With the more widespread application of tacrolimus in organ transplantation , tacrolimus - associated TMA has also been recognized .
### Output Text:
With the more widespread application of <span class="chemical">tacrolimus</span> in organ transplantation , <span class="chemical">tacrolimus</span> - associated TMA has also been recognized . 