Pluripotency-related gene expression by quantitative (q)PCR. Gene expression levels were normalized against 18S rRNA. The ratio of the relative expression for each gene to 18S was calculated by using the 2-ΔΔCq formula. hiPSC data were used as a calibrator for the results presented (100%). (A) OCT4 and KLF4; (B) NANOG, SOX2 and REX1.