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: We propose that remoxipride and benzene may induce aplastic anemia via production of similar reactive metabolites and that the ability of NCQ436 and NCQ344 to induce apoptosis in HBMP cells may contribute to the mechanism underlying acquired aplastic anemia that has been associated with remoxipride .
### Output Text:
We propose that <span class="chemical">remoxipride</span> and <span class="chemical">benzene</span> may induce aplastic anemia via production of similar reactive metabolites and that the ability of <span class="chemical">NCQ436</span> and <span class="chemical">NCQ344</span> to induce apoptosis in HBMP cells may contribute to the mechanism underlying acquired aplastic anemia that has been associated with <span class="chemical">remoxipride</span> . 