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: Primary end points were study compliance , increases in liver transaminases to > 3 times the upper limit of normal , and clinical myopathy .
### Output Text:
Primary end points were study compliance , increases in liver transaminases to > 3 times the upper limit of normal , and clinical myopathy . 