These CSC subpopulations have been characterized in several subtypes of sarcomas and associated to the expression/activity of pluripotency factors, like Sex Determining Region Y-Box 2 (SOX2), stem cell markers, like Aldehyde Dehydrogenase 1 Family Member A1 (ALDH1), or to the ability to grow as floating clonal spheres (tumorspheres) [13,14]. The gene discussed is ALDH1A1; the disease is sarcoma.