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: Introducing chromosome 5 , encoding the MSH3 gene , into the mutant cell line increased the stability of some but not all microsatellites .
### Output Text:
Introducing chromosome 5 , encoding the MSH3 gene , into the mutant cell line increased the stability of some but not all microsatellites . 