the type i igf receptor consists of two species of subunits : alpha-subunits ( mol . wt . approximately 115 000 ) , which bind igf i and igf ii with almost equal affinity and beta-subunits ( mol . wt . approximately 94 000 ) , the phosphorylation of which is stimulated by igfs .
C0021666
igf ii
C0037657
igfs