CTCFL and cancer: To better understand the functional interplay between CTCF and BORIS in human cells, we performed ChIP-seq in three cancer cell lines — K562 (chronic myelogenous leukemia line), Delta47 (multiple myeloma line), and OVCAR8 (ovarian cancer line) — all of which express comparable levels of CTCF and BORIS proteins in the nucleus (Fig. S1a–c in Additional file 1).