GR-sensitive cases present with an accessible (open) IGR locus and lower DNA methylation at this locus, compared with GR-resistant tumors.171 This conformation permits the binding of the GR and the insulator protein CTCF to enhance BIM transcription, contributing to the acute sensitivity of normal and malignant lymphocytes to GC-induced apoptosis.171 Thus, this lymphocyte-specific chromatin conformation can determine GC resistance in ALL. The gene discussed is NR3C1; the disease is acute lymphoblastic leukemia.