> as lemmas

1975 Nature 11 Sept. 89/2 The existence of an analogous precursor to insulin, a preproinsulin, was strongly supported by the experiments of M. A. Permutt.

1979 Nature 21 June 675/1 The gene coding for preproinsulin II contained an additional intron of about 500 nucleotides between the region encoding amino acids 38 and 39 of the proinsulin II peptide chain.

1991 D. J. Weatherall New Genet. & Clin. Pract. (ed. 3) iii. 46 Insulin..is first synthesized as a molecule called preproinsulin which is 110 amino acids long.