2512
Four of 6 cases tested showed functional NK cell-mediated cytotoxicity , suggesting a relationship between these unique CD33+, CD56+, CD16 -acute leukemias and normal CD56+, CD16- NK precursor cells .
 ( protein: CD16, None) , ( cell type: normal CD56+, CD16- NK precursor 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:
 ( protein: CD16, None) , ( cell type: normal CD56+, CD16- NK precursor cells, None) 