Differentiation of blood-derived iPSCs in vitro and in vivo. (a) Blood-derived iPSC clones were spontaneously differentiated through embryoid body formation, and analyzed via immunocytochemistry for lineage markers for three embryonic germ layers (endoderm FOXA2, mesoderm CD31, and ectoderm β-III-tubulin). (b) Transplantation of iPSCs into renal capsule of SCID-beige mice resulted in teratoma formation. Tissue histology of teratomas demonstrated the cells of three germ layers including glandular, muscular, and neural rosette-like tissues. (c) Schematic diagram describing the stepwise-guided differentiation protocol for iPSC differentiation into islet-like cells. ActA, Activin A; CYC, cyclopamine; DE, definitive endoderm; FGF10, fibroblast growth factor 10; GLP-1, glucagon-like peptide-1; HGF1, hepatocyte growth factor-1; IGF, insulin-like growth factor-1; ILV, indolactam V; ISL, islet-like cells; PE, pancreatic endoderm; PG, primitive gut; RA, all-trans retinoic acid; Wnt, Wnt3a. (d) Through the guided differentiation protocol, HPC- or PBMC-derived iPSC clones were induced to definitive endoderm (day 5), pancreatic endoderm (day 10), and insulin-producing islet-like cells (day 24). Immunostaining demonstrated the expression of stage-specific markers in iPSC progeny at day 5 (FOXA2 and SOX17), day 10 (NKX6.1 and PDX1), and day 24 (INS). Scale bars indicate 50 μm.