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 study evaluated 4 patients with FMF who had been taking colchicine on a long - term basis .
### Output Text:
The study evaluated 4 patients with <span class="disease">FMF</span> who had been taking colchicine on a long - term basis . 