Samples were then treated with 2 µg RNaseA (Novagen; Darmstadt, Germany) at 37°C for 15 minutes, then with 2 µg Proteinase K at 55°C for 30 minutes (Cell Signaling Technology).
Immunoprecipiated DNA fragments were extracted by Phenol-Chloroform (Sigma-Aldrich) extraction and subjected to Q-RT-PCR using commercially available SimpleChIP™ Human Sox2 cis-enhancer promoter primers (Cell Signaling Technology).