Expression of the effector gene results in {TAIL ~ expression} of a cell surface antigen that can be used to deplete {HEAD ~ the undifferentiated cells} 
Expression of the effector gene results in { TAIL ~ expression } of a cell surface antigen that can be used to deplete { HEAD ~ the undifferentiated cells }
OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD