For exogenous expression of Rich△BAR had no effect on the CSCs-like properties in breast cancer, and the deletion of BAR domain in RICH1 could not reduce the GTPase hydrolyzing function for Cdc42 (data not shown), we suggested that the potential RICH1-Cdc42-F-actin-YAP/TAZ regulatory axis was of little significance in the regulation of tumor stemness. The gene discussed is CDC42; the disease is breast cancer.