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: Targeting an alternative signaling pathway , such as PKC - mediated signaling , may be an effective method of treating lithium - induced polyuria .
### Output Text:
Targeting an alternative signaling pathway , such as PKC - mediated signaling , may be an effective method of treating <span class="chemical">lithium</span> - induced polyuria . 