EFEMP1 and glioma: FLAG-tagged, wild-type EFEMP1 protein construct (E1) and FLAG-tagged EFEMP1 protein-variant constructs were made in mammalian expression vector pcDNA3.1+ and lentiviral vector pTRIPZ, then transfected or infected, respectively, into glioma cell lines U251 and its clonal neural sphere culture U251-NS.