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: Improved familiarity of healthcare professionals with argatroban therapy in HIT , including in special populations and during PCI , may facilitate reduction of harm associated with HIT ( e . g . fewer thromboses ) or its treatment ( e . g . fewer argatroban medication errors ) .
### Output Text:
Improved familiarity of healthcare professionals with <span class="chemical">argatroban</span> therapy in HIT , including in special populations and during PCI , may facilitate reduction of harm associated with HIT ( e . g . fewer thromboses ) or its treatment ( e . g . fewer <span class="chemical">argatroban</span> medication errors ) . 