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: Four binary comparisons were made : WT control versus CYP treatment ( 48 h ) , VIP ( - / - ) control versus CYP treatment ( 48 h ) , WT control versus VIP ( - / - ) control , and WT with CYP treatment ( 48 h ) versus VIP ( - / - ) with CYP treatment ( 48 h ) .
### Output Text:
Four binary comparisons were made : WT control versus <span class="chemical">CYP</span> treatment ( 48 h ) , VIP ( - / - ) control versus <span class="chemical">CYP</span> treatment ( 48 h ) , WT control versus VIP ( - / - ) control , and WT with <span class="chemical">CYP</span> treatment ( 48 h ) versus VIP ( - / - ) with <span class="chemical">CYP</span> treatment ( 48 h ) . 