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: Despite high levels of mRNA expression , there was no evidence of the HD gene product in any of these transgenic mice .
### Output Text:
Despite high levels of mRNA expression , there was no evidence of the <span class="disease">HD</span> gene product in any of these transgenic mice . 