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: A similar pattern was observed for follicular cell lymphoma , but no other lymphoma subtypes .
### Output Text:
A similar pattern was observed for follicular cell lymphoma , but no other lymphoma subtypes . 