NANOG and breast cancer: Moreover, the chromatin-immunoprecipitation-quantitative polymerase chain reaction (ChIP-qPCR) assay showed that TAZ and NANOG were enriched at the promoter regions of SOX2 and OCT4 in breast cancer cells grown on stiff supports but not cells grown on soft supports (Fig. 6e, f), thus suggesting that TAZ/NANOG could activate Sox2 and Pou5f1 (encoding OCT4) transcription by binding their promoters.