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: Heart and liver patients had more infections than cyclosporine renal patients but fewer infections than the Aza renal patients .
### Output Text:
Heart and liver patients had more infections than <span class="chemical">cyclosporine</span> renal patients but fewer infections than the <span class="chemical">Aza</span> renal patients . 