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: In addition , somatic Inactivation of the VHL gene is frequent in sporadic renal cell carcinoma and haemangioblastoma .
### Output Text:
In addition , somatic Inactivation of the <span class="disease">VHL</span> gene is frequent in <span class="disease">sporadic renal cell carcinoma</span> and <span class="disease">haemangioblastoma</span> . 