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 preliminary screens , mutations of PTEN were detected in 31 % ( 13 / 42 ) of glioblastoma cell lines and xenografts , 100 % ( 4 / 4 ) of prostate cancer cell lines , 6 % ( 4 / 65 ) of breast cancer cell lines and xenografts , and 17 % ( 3 / 18 ) of primary glioblastomas .
### Output Text:
In preliminary screens , mutations of PTEN were detected in 31 % ( 13 / 42 ) of <span class="disease">glioblastoma</span> cell lines and xenografts , 100 % ( 4 / 4 ) of <span class="disease">prostate cancer</span> cell lines , 6 % ( 4 / 65 ) of <span class="disease">breast cancer</span> cell lines and xenografts , and 17 % ( 3 / 18 ) of <span class="disease">primary glioblastomas</span> . 