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: Analysis is reported on 37 patients with a minimum of 6 months follow - up who received a total of 192 cycles of TFL : nine cycles ( 5 % ) were associated with grade 3 / 4 neutropenia requiring hospitalization ; seven ( 4 % ) cycles in two patients required granulocyte colony - stimulating factor due to neutropenia ; no patient required platelet transfusions .
### Output Text:
Analysis is reported on 37 patients with a minimum of 6 months follow - up who received a total of 192 cycles of TFL : nine cycles ( 5 % ) were associated with grade 3 / 4 neutropenia requiring hospitalization ; seven ( 4 % ) cycles in two patients required <span class="chemical">granulocyte colony - stimulating factor</span> due to neutropenia ; no patient required platelet transfusions . 