In the sentence extracted from biomedical literature, identify all the chemical entities. The required answer format is the same sentence with HTML <span> tags to mark up specific entities. 
### Entity Markup Guides:
Use <span class="chemical"> to denote a chemical.

### Input Text: Antitumor activity , cardiotoxicity , and nephrotoxicity induced by doxorubicin were studied in LOU / M / WSL inbred rats each bearing a transplantable solid IgM immunocytoma .
### Output Text:
Antitumor activity , cardiotoxicity , and nephrotoxicity induced by <span class="chemical">doxorubicin</span> were studied in LOU / M / WSL inbred rats each bearing a transplantable solid IgM immunocytoma . 