GLI2 and breast carcinoma: Indeed, human bone marrow HS5 and primary bone marrow stromal cells were found to be paracrine sources of Wnt3a ligands, and treatment of breast cancer MDA-MB-231 cells with conditioned media derived from these stromal cells enhanced GLI2 levels, which was also associated with an increase in PTHrP (osteolysis mediator) levels and bone destruction.