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We observed that RA did not induced neutrophil differentiation in serum-free grown HL60 cells whereas 50 nM 1 alpha,25-dihydroxyvitamin D3 ( D3 ) induced maximal monocyte differentiation .
 cell line: HL60 cells; cell line: serum-free grown HL60 cells
Given options, please tell me the categories of all the listed entity words.Output format is "type1: word1; type2: word2". 
Option: cell line, protein, RNA, DNA, cell type 
Text: {0} 
 Entities: HL60 cells, serum-free grown HL60 cells 
Answer:
 cell line: HL60 cells; cell line: serum-free grown HL60 cells