RCN1 and glioblastoma: As EGFRvIII expression correlated with RCN1 expression and as the wt EGFR associated with RCN1, we next examined 3 glioblastoma cell lines with increased wt EGFR compared to their parental counterparts either through stable transfection (U87wtEGFR) or through selection and re-population of single cells isolated from the original overall parental population—designated U87-SCD and U251-SCD for single cell dilution.