IRS1 and {HEAD ~ IRS2} are {TAIL ~ part} of the insulin or insulin like growth factor signaling pathway 
are
IRS1 and { HEAD ~ IRS2 } are { TAIL ~ part } of the insulin or insulin like growth factor signaling pathway
OTH OTH HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH