POU5F1 and sarcoma: To further confirm the ability of MTM formulations to target CSC subpopulations in sarcomas, we made use of a previously developed model of undifferentiated pleomorphic sarcoma (T-5 H-O cells) expressing a lentiviral reporter system which include a composite SOX2/OCT4 response element (SORE6) coupled to a cytomegalovirus promoter to drive the expression of the GFP reporter gene (T-5 H-O-SORE-GFP cells) [25, 36].