binding of [ 125i ] igf-i to islet a cells was half-maximally inhibited by 7.10 ( -10 ) m igf-i , while igf-ii , insulin , and proinsulin were respectively 10- , 500- , and 10,000-fold less potent displacers of igf-i binding .
C0021641
insulin
C0033362
proinsulin