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: Although the specific gene inactivated by this allelic loss has not been elucidated , the DCC ( deleted in colorectal cancer ) gene is a candidate .
### Output Text:
Although the specific gene inactivated by this allelic loss has not been elucidated , the DCC ( deleted in <span class="disease">colorectal cancer</span> ) gene is a candidate . 