MBD4 and breast cancer: 16 using RNA‐sequencing and microarray gene expression profiling demonstrated that RNF144A is one of 192 genes that are regulated by MBD4 through aberrant DNA methylation in human breast cancer cells. However, we cannot rule out the possibility that inhibition of MBD4 resulting in increased expression of RNF144A could be mediated by DNA methylation‐independent pathways. In addition, a possible limitation of the present study was the relatively small sample size of patient samples and breast cancer cell lines used in the RNA144A promoter methylation analyses.