Consideration of {TAIL ~ that question} raises {HEAD ~ issues} of complement fixation and the like, which then drives the selection of the particular class or isotype of antibody 
Consideration of { TAIL ~ that question } raises { HEAD ~ issues } of complement fixation and the like , which then drives the selection of the particular class or isotype of antibody
OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH