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: Of 388 liver recipients who received tacrolimus as primary immunosuppression , 70 required conversion to CyA .
### Output Text:
Of 388 liver recipients who received <span class="chemical">tacrolimus</span> as primary immunosuppression , 70 required conversion to CyA . 