KD of BPTF results in greater nucleosome occupancy within the 5′HS4 insulator. (A) Mapping of the nucleosome occupancy in the 5′HS4 insulator element by a nucleosome scanning assay in 6C2 809 cells harboring the pSuper control or shBPTF. (B) Schematic representation of the insulated IL2R transgene and the position of PCR primer sets used in ChIP analysis. (C-D) ChIP analysis of trimethyl H3K27 and dimethyl H3K9 at the flanking 5′HS4 sites and at the integrated IL2R transgenes comparing the pSuper control transfected and BPTF KD 809 cells, respectively. *P < .05 and **P < .01 by Student t test. Shown are the means ± SEM of 3 independent experiments.