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: DNA sequencing of the exon - intron junctions revealed a number of revisions regarding the boundaries between exons 4 , 5 , and 6 as well as between exons 10 and 11 .
### Output Text:
DNA sequencing of the exon - intron junctions revealed a number of revisions regarding the boundaries between exons 4 , 5 , and 6 as well as between exons 10 and 11 . 