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: METHODS : We identified seven SNP ( single nucleotide polymorphism ) ( - 141Cins > del , TaqIB , TaqID , Ser311Cys , rs6275 , rs6277 and TaqIA ) in the DRD2 gene in 146 schizophrenic inpatients ( 59 with EPS and 87 without EPS according to the Simpson - Angus Scale ) treated with chlorpromazine after 8 weeks .
### Output Text:
METHODS : We identified seven SNP ( single nucleotide polymorphism ) ( - 141Cins > del , TaqIB , TaqID , Ser311Cys , rs6275 , rs6277 and TaqIA ) in the DRD2 gene in 146 schizophrenic inpatients ( 59 with EPS and 87 without EPS according to the Simpson - Angus Scale ) treated with <span class="chemical">chlorpromazine</span> after 8 weeks . 