PIWIL1 and glioblastoma: The underlying molecular mechanisms remain largely unknown, but a study in glioblastoma stem cells revealed that PIWIL1 downregulation reduced c-MYC levels and strongly increased BTG2 (B cell translocation gene 2), a tumor suppressor, and FBXW7 (F-Box WD Repeat Domain Containing 7), a component of the SCF (Skp, Cullin, F-box containing) complex, which regulates the stability of proteins such as c-MYC.