Supplementary figure 1. Characterization of INS^{Cherry/Cherry} (INS^Δ123/Δ123) reporter iPSC line. a) PCR analyses for genotyping WT, INS^cherry/wt and INS^{cherry/cherry} clones. b) INS^{cherry/cherry} is characterized by a normal female karyotype (46, XX). c) SOX2 and OCT3/4 expression in INS^{cherry/cherry} clone. Scale bar, 80 μm. d) IHC of directed differentiation of INS^{cherry/cherry} in-vitro towards the three germ layers, endoderm, mesoderm and ectoderm. Scale bar 50 μm for endoderm and mesoderm and 100 μm for ectoderm. e) Schematic representation of human in-vitro endocrine differentiation stages. f) IHC showing definitive endoderm (DE), pancreatic progenitor (PP2) and endocrine cells, confirms in-vitro differentiation capacity of INS^{cherry/cherry} clone. Scale bar, 80 μm. g) Live imaging detecting H2B-Cherry signal in INS^{Cherry/cherry} cells at S6 confirming insulin promoter activity. Schemes were created with BioRender.com.