In the sentence extracted from biomedical literature, identify all the disease entities. The required answer format is the same sentence with HTML <span> tags to mark up specific entities. 
### Entity Markup Guides:
Use <span class="disease"> to denote a disease.

### Input Text: Transporter - facilitated uptake of serotonin ( 5 - hydroxytryptamine or 5 - HT ) has been implicated in anxiety in humans and animal models and is the site of action of widely used uptake - inhibiting antidepressant and antianxiety drugs .
### Output Text:
Transporter - facilitated uptake of serotonin ( 5 - hydroxytryptamine or 5 - HT ) has been implicated in <span class="disease">anxiety</span> in humans and animal models and is the site of action of widely used uptake - inhibiting antidepressant and antianxiety drugs . 