PROM1 and adenoid cystic carcinoma: In contrast to normal salivary gland cells, they expressed ACC markers previously introduced to validate stem cell identity of cultured cells (SOX10, NOTCH1, FABP7, NTRK3/TrkC and PROM1/CD133), and formed spheroids in 3D cultures and tumors in immunodeficient mice, proving to be a useful source for adenoid cystic carcinoma samples for personalized oncology.