5150
We investigated the regulation of thymidine kinase in phytohemagglutinin -stimulated normal human lymphocytes and in the p16 -negative human acute lymphoblastic leukemia cell lines , MOLT-4 and CEM .
 ( protein: phytohemagglutinin, None) , ( cell line: CEM, None) , ( cell line: MOLT-4, None) , ( protein: thymidine kinase, None) , ( protein: p16, None) , ( cell line: p16 -negative human acute lymphoblastic leukemia cell lines, None) , ( cell line: phytohemagglutinin -stimulated normal human lymphocytes, 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: phytohemagglutinin, None) , ( cell line: CEM, None) , ( cell line: MOLT-4, None) , ( protein: thymidine kinase, None) , ( protein: p16, None) , ( cell line: p16 -negative human acute lymphoblastic leukemia cell lines, None) , ( cell line: phytohemagglutinin -stimulated normal human lymphocytes, None) 