TFF3 and breast cancer: Similarly to our experimental models, the relevance of TFF3 as an epithelial like CTC-associated marker was confirmed in a cohort of 17 M0 and 27 M+ breast cancer patients as TFF3 was found more frequently expressed in EPCAM+ve compared to EPCAM-ve CTC-enriched samples collected before starting therapy (Fig. 4L; p-value=0.0225).