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 sG145R mutation strongly reduced HBsAg levels and was able to fully restore the impaired replication of LAM - resistant HBV mutants to the levels of wild - type HBV , and PC or BCP mutations further enhanced viral replication .
### Output Text:
The sG145R mutation strongly reduced <span class="chemical">HBsAg</span> levels and was able to fully restore the impaired replication of <span class="chemical">LAM</span> - resistant HBV mutants to the levels of wild - type HBV , and PC or BCP mutations further enhanced viral replication . 