In certain embodiments, {HEAD ~ P X} is {TAIL ~ an introduced heterologous molecule}, meaning that the cell or its ancestors was genetically altered with a vector comprising P X 
In certain embodiments , { HEAD ~ P X } is { TAIL ~ an introduced heterologous molecule } , meaning that the cell or its ancestors was genetically altered with a vector comprising P X
OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH