To demonstrate the tumorigenic capacity of ovarian CSCs enriched and prepared to be used for the ChemoID® assay, we performed limiting dilution tumorigenicity experiments by injecting intraperitoneally in nude mice 1 × 10^2 CSCs derived from a biopsy of one of the patients affected by ovarian cancer, which were sorted by a column using specific antibodies against CD44, CD117, or CD133 (Mylteni) magnetically bound and compared their growth to 1 × 10^6 non-CSCs cells (negative for the CD markers). Here, CD44 is linked to ovarian cancer.