CD133 has been extensively used as a CSC marker in many tumours [86], including brain [87], breast [88], colon [89], liver [90, 91], lung [92], melanoma [93, 94] and ovarian [95–97] cancers, although there are limited reports on the relationship between CD133-positivity and the stem-like characteristics of tumour cells. Here, PROM1 is linked to cancer.