{HEAD ~ Transgenic animals} for producing {TAIL ~ specific isotypes} of human antibodies via non cognate switch regions 
for producing
{ HEAD ~ Transgenic animals } for producing { TAIL ~ specific isotypes } of human antibodies via non cognate switch regions
HEAD HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH