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: Susceptibility to breast cancer did not appear to be affected by the presence of rare HRAS1 alleles .
### Output Text:
Susceptibility to <span class="disease">breast cancer</span> did not appear to be affected by the presence of rare HRAS1 alleles . 