We showed here that GNB4 was downregulated in both fulvestrant- and tamoxifen-resistant breast cancer cell lines, and that this was attributed to DNMT3B-mediated DNA methylation, because knockdown of DNMT3B by siRNA significantly elevated the expression of GNB4 at both mRNA and protein levels (Fig. 2). The gene discussed is DNMT3B; the disease is breast carcinoma.