6679
We demonstrate here that the biological effect of PNU156804 in vitro is indistinguishable from UP : PNU156804 blocks human T cell proliferation in mid-late G1 , as determined by cell cycle analysis , expression of cyclins , and cyclin-dependent kinases and retinoblastoma phosphorylation .
 ( protein: cyclins, None) , ( protein: cyclin-dependent kinases, None) , ( cell type: human T cell, 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: cyclins, None) , ( protein: cyclin-dependent kinases, None) , ( cell type: human T cell, None) 