MSH6 and glioblastoma: In human GBM tissues, the oncogene MSH6, CXCR4 and TGF-β1 form a triangular feedback loop that accelerates gliomagenesis, proliferation, migration/invasion, EMT, stemness, angiogenesis and survival by regulating the STAT3/Slug and Smad2/3/ZEB2 signaling pathways.