The broad heterogeneity of CTCs of cancer patients, including ovarian cancer, has already been demonstrated [17–19] and we may speculate that, besides the presence of epithelial, stem cell-like or potentially platinum-resistant ERCC1-expressing CTCs, some other CTC-phenotypes may play a dominant role for therapy resistance and recurrence in ovarian cancer patients. Here, ERCC1 is linked to ovarian carcinoma.