14229
The proliferation and NK activity of YT-N17 (a human NK-like cell line ) were enhanced by 17 beta-estradiol ( E2 ), and the enhancement was blocked by tamoxifen ( Tx ), an antagonist of E2 .
 ( cell line: YT-N17, None) , ( cell line: human NK-like cell line, 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: YT-N17, None) , ( cell line: human NK-like cell line, None) 