Issues

High-level EGFR gene amplification can be retained in glioblastoma stem-like cell lines established and propagated without recombinant EGF. In contrast, high-level amplification is lost in parallel cell lines from the same tumors established with EGF supplementation. Cell lines with high-level EGFR amplification produce highly aggressive xenograft tumors in the brains of nude mice, retaining the EGFR amplification as shown in the cover figure, whereas counterpart cell lines, lacking high-level amplification, are either nontumorigenic or grow significantly more slowly in vivo. For details, see the article by Schulte and colleagues on page 1901 of this issue.