The dimerization propensity metric was compared to experimental dimerization data from Guan et al. . Dimerization data exists only for wild type, GF 9, GF 10, and GF 13, and thus comparisons between experimental and computational data proved challenging. We focused only on residues GlyB23-TyrB26 because these are the dimer interface residues that form backbone hydrogen bonds with another insulin monomer (Figure ) .