TP53 and breast cancer: First, a gene expression dataset consisting of 251 consecutively collected breast cancers [6] displayed low RIC8A transcript levels in 15% of the tumours and a significant association was shown between low RIC8A gene expression and ER-negativity (P < 0.001), PR-negativity (P < 0.003) and TP53 mutation (P < 0.0001) (Figure 3A).