A variety of publications support the hypothesis that iPSCs generated from different primary cell sources share most characteristics with embryonic stem cells [7, 16, 17, 36, 37]. Immunofluorescence staining, methylation assays, teratoma formation assays, karyotyping, or bisulfite genomic sequencing are only a selection of methods commonly used to prove the potential of differentiation into all three germ layers and pluripotency capacity of the generated iPSCs. Hence, no significant differences were published concerning the primary cell source and their respective behavior as reprogrammed stem cells, although a variety of divergences are observed between iPS clones.
