328
The mRNA for the Duffy blood group antigen , the erythrocyte receptor for the Plasmodium vivax malaria parasite , has recently been cloned and shown to encode a widely expressed chemokine receptor .
 ( protein: chemokine receptor, None) , ( protein: Duffy blood group antigen, None) , ( RNA: mRNA, None) , ( protein: erythrocyte receptor, None) 
Locate the role in the text that participated in the event based on the event type and return it in the event list. 
 Option: Event type: RNA,cell type,protein,cell line,DNA, Arguments type: . 
Text: {0} 
Answer:
 ( protein: chemokine receptor, None) , ( protein: Duffy blood group antigen, None) , ( RNA: mRNA, None) , ( protein: erythrocyte receptor, None) 