Correlation analysis between the CEUS quantitative parameters of breast cancers and the relative expression levels of CSC- and EMT-related mRNAs showed that the peak intensity was positively related to the expression levels of the CSCs marker CD44 and the interstitial marker N-cadherin, while the starting time of enhancement was negatively related to the expression of interstitial marker N-cadherin. The gene discussed is CD44; the disease is breast cancer.