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: Response was not influenced by the initial neutrophil count , with a 62 % cure rate for 39 episodes associated with severe neutropenia .
### Output Text:
Response was not influenced by the initial neutrophil count , with a 62 % cure rate for 39 episodes associated with severe neutropenia . 