{HEAD ~ Whole body irradiation} is often used in {TAIL ~ the art} to create hematopoietic space and thus promote engraftment, chimerism, and tolerance 
{ HEAD ~ Whole body irradiation } is often used in { TAIL ~ the art } to create hematopoietic space and thus promote engraftment , chimerism , and tolerance
HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL OTH REL REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH