NANOG DNA methylation pattern at individual CpG sites. Lines reflect sample type. MSssi-treated samples are included for comparison. Letters (A, B, C) denote statistical differences (P≤0.05) between (A) iPS cells, fetal cells, MPCs, or chondrocytes; (B) fetal cells, MPCs, or chondrocytes; (C) MPCs versus chondrocytes. iPS, induced pluripotent stem.