This finding goes some way towards explaining the apparent opposite roles of RNF20 and H2Bub1 in basal and luminal breast cancers, whereby RNF20 and H2Bub1 appear to function in a tumour-suppressive role in basal-like breast cancer cells and be pro-oncogenic in luminal breast cancer cells, driving tumorigenesis. Here, RNF20 is linked to breast carcinoma.