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: Simvastatin plasma concentration increased 30 times in this patient and statin induced muscle toxicity is related to the concentration of the statin in blood .
### Output Text:
<span class="chemical">Simvastatin</span> plasma concentration increased 30 times in this patient and <span class="chemical">statin</span> induced muscle toxicity is related to the concentration of the <span class="chemical">statin</span> in blood . 