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: No significant differences were found in the molecular layer or the granule cell layer , which included labeled neurons along the lower margin of the granule cell layer .
### Output Text:
No significant differences were found in the molecular layer or the granule cell layer , which included labeled neurons along the lower margin of the granule cell layer . 