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: The PAX3 - FKHR fusion product retains the DNA binding domains of the PAX3 protein and the putative activator domain of the FKHR protein .
### Output Text:
The PAX3 - FKHR fusion product retains the DNA binding domains of the PAX3 protein and the putative activator domain of the FKHR protein . 