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: atm and p53 cooperate in apoptosis and suppression of tumorigenesis , but not in resistance to acute radiation toxicity .
### Output Text:
atm and p53 cooperate in apoptosis and suppression of tumorigenesis , but not in resistance to <span class="disease">acute radiation toxicity</span> . 