Recent studies have shown that enhanced MLL3 and SETD1A expression promotes ERα expression to support tamoxifen-resistant breast cancer proliferation, and genome-wide histone methylation studies have revealed that MLL3 is required for acetylation of H3K27 and monomethylation of H3K4 in the ERα enhancer [111]. The gene discussed is ESR1; the disease is breast carcinoma.