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: Apoptosis has recently been recognized as a mode of cell death in Huntington disease ( HD ) .
### Output Text:
Apoptosis has recently been recognized as a mode of cell death in <span class="disease">Huntington disease</span> ( <span class="disease">HD</span> ) . 