Therefore, we performed direct bisulfite DNA sequencing of the regions flanking the three CTCF binding sites within BLU gene from such NSCLC patients (i.e. patients 30, 42, 4 and 15 selected from Fig. 1B and 1C) as well as IMR90 normal lung cell line and H1299 lung cancer cell line. The gene discussed is CTCF; the disease is lung cancer.