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 present study confirms the involvement of BRCA1 in disease predisposition for a subset of hereditary breast cancer families often characterized by ovarian cancers .
### Output Text:
The present study confirms the involvement of BRCA1 in disease predisposition for a subset of <span class="disease">hereditary breast cancer</span> families often characterized by <span class="disease">ovarian cancers</span> . 