The NDR promoters, unlike the NP promoters, were enriched for binding motifs for specific transcription factors such as SP1 and NRF1 (Supplemental Fig. 6), typical “housekeeping” transcription factors that normally protect CGI promoters from methylation in both normal and cancer cells (Gebhard et al. 2010; Berman et al. 2012). Here, NRF1 is linked to cancer.