Interestingly, methyl-CpG islands in the GR promoter work as a binding site for Kaiso, a pox virus, and zinc finger (transcription factor), resulting in the repression of GR expression in ERα-positive breast cancer cells (MCF-7 and T47D), attenuating GR anti-apoptotic activity [113]. The gene discussed is NR3C1; the disease is breast cancer.