Finally, an important practical implication of our data is that both fibroblasts and blood can be used for the generation of comparable iPSC lines for large-scale biobanking purposes (Figure 6). Our results demonstrate that variability among small cohorts of iPSCs may lead to erroneous conclusions (Sandoe and Eggan, 2013). Because of the inherent differences resulting from the donor-dependent variability, it seems obvious that relatively large cohorts of iPSC lines from different donors, rather than several isogenic clones from a few donors, would be needed to obtain reliable results concerning the impact of donor-specific variants. However, the fact that intra-individual clonal variation is still present after careful technical standardization and iPSC characterization also suggests that genetically matched clones from the donor should be available in biobanks.
