ERBB2 and bone metastasis: OS was significantly lower according to Kaplan–Meier estimates in patients with bone metastasis positive for CK-19 (21.3 mo vs. 49.7 mo, p = 0.046) (Figure S1A), CD44high/CD24low (17.4 mo vs. 49.4 mo; p = 0.005) (Figure S1B), ALDH1high/CD24low (6.0 mo vs. 45.9 mo; p = 0.002) (Figure S1C) and HER2 (20.7 mo vs. 50.9 mo; p = 0.030) (Figure S1D), compared to patients who were negative for these gene transcripts in EpCAM(+) CTCs.