PAX4 and diabetes mellitus: Skin biopsies and/or blood samples from recruited donors without diabetes were used to derive hiPSCs of the following genotypes: homozygous for the PAX4 p.Arg192 and p.Tyr186 alleles (wildtype), heterozygous for either the p.Arg192His or p.Tyr186X alleles, and homozygous for the p.His192 allele (p.His192His) (Fig. 4a).