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: Furthermore , it was observed that TAM inhibits the peroxidation of human erythrocytes induced by AAPH , thus ruling out TAM - induced cell oxidative stress .
### Output Text:
Furthermore , it was observed that <span class="chemical">TAM</span> inhibits the peroxidation of human erythrocytes induced by <span class="chemical">AAPH</span> , thus ruling out <span class="chemical">TAM</span> - induced cell oxidative stress . 