Figure 5: Overall evaluation of cancer risk. By using real time qPCR with TaqMan-gene-specific primers for four re-programming genes (cMyc, Oct4, Sox2, Klf4) plus two stem cell bio-markers SSEA1 and Nanog, the overall potential cancer risk was assessed by comparing 6-month bulk cultured re-programmed stem cellderived dopaminergic neurons with other 3 control groups: original non-reprogrammed mouse tail-tip cells from parallel cultures, original mice midbrain tissues, and original mice tail tissues. There were no significant differences in the gene expressions of all biomarkers among the four groups. The values of the gene expressions were normalized to the level of control housekeeping gene GAPDH.