EPCAM and carcinoma: Primary carcinomas, metastases, and cancer stem cells express high levels of EpCAM too (Baeuerle and Gires, 2007; Gires et al., 2009; Went et al., 2004), whereas circulating and disseminated tumor cells (CTCs/DTCs) display heterogeneous EpCAM expression with frequent loss during EMT (Brown et al., 2021; Gires and Stoecklein, 2014; Gorges et al., 2012; Keller et al., 2019; Liu et al., 2019).