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: The only sign of a possible involvement is the increase in the number of specific granules with a presumed lysosomal function in the superficial cells .
### Output Text:
The only sign of a possible involvement is the increase in the number of specific granules with a presumed lysosomal function in the superficial cells . 