Since the close link between RICH1 and other upstream regulators of the Hippo signaling has been demonstrated in several previous studies [13, 20], and the core transcriptional coactivators YAP/TAZ of Hippo pathway have been identified as key regulators of CSCs-related traits on breast cancer cells, we further used the STRING database to predict the protein-protein interaction network of RICH1-associated molecules and found that RICH1 was involved in the regulatory network of Hippo signaling via interaction with Merlin or Amot (Fig. 5A). This evidence concerns the gene AMOT and breast cancer.