Table 2 presents the number of samples expressing analyzed genes according to this positivity criterion. Fifty-five percent (54/98) of the patient samples with invasive tumors were positive for either CK19, MGB1 or HER2. In total, 26% of the samples expressed at least one EMT marker (VIM, TWIST1, SNAIL or SLUG). No healthy control expressed CTCs markers, whereas in all three cases of DCIS expression of at least one CTC marker was detected (Table 2 and Figure S2). Here, SNAI1 is linked to ductal breast carcinoma in situ.