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: Like BRCA1 , BRCA2 behaves as a dominantly inherited tumour suppressor gene .
### Output Text:
Like BRCA1 , BRCA2 behaves as a dominantly inherited <span class="disease">tumour</span> suppressor gene . 