14327
In contrast to MEL cells , however, K562 cells acquired a macrophage-like morphology and exhibited a complete failure to generate benzidine-positive cells .
 ( cell line: K562 cells, None) , ( cell line: benzidine-positive cells, None) , ( cell line: MEL cells, 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:
 ( cell line: K562 cells, None) , ( cell line: benzidine-positive cells, None) , ( cell line: MEL cells, None) 