1550
GP Ib alpha promoter activity was evaluated by transfection of human erythroleukemia cells with reporter plasmids coding for the enzyme , luciferase .
 protein: enzyme; protein: luciferase; cell type: human erythroleukemia cells; protein: GP; DNA: GP Ib alpha promoter
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: cell line, protein, RNA, DNA, cell type 
Text: {0} 
Answer:
 protein: enzyme; protein: luciferase; cell type: human erythroleukemia cells; protein: GP; DNA: GP Ib alpha promoter