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: CONCLUSION : HTR6 may play an important role in the pathophysiology of METH - induced psychosis in the Japanese population .
### Output Text:
CONCLUSION : HTR6 may play an important role in the pathophysiology of <span class="chemical">METH</span> - induced psychosis in the Japanese population . 