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 cholesteryl ester transfer protein ( CETP ) mediates the transfer of cholesteryl esters from HDL to other lipoproteins and is a key participant in the reverse transport of cholesterol from the periphery to the liver .
### Output Text:
The cholesteryl ester transfer protein ( CETP ) mediates the transfer of cholesteryl esters from HDL to other lipoproteins and is a key participant in the reverse transport of cholesterol from the periphery to the liver . 