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: Multiple chromosomes have been found as the translocation partners of chromosome 12 but 3q27 - q28 is preferentially involved .
### Output Text:
Multiple chromosomes have been found as the translocation partners of chromosome 12 but 3q27 - q28 is preferentially involved . 