After screening five common glioma cell lines (T98G, HGL21, U87, U373, U138) for expression of PDGF-C (see Figure 1B), we chose U87MG as the parental line because of its relatively modest levels of PDGF-C, which made it possible to effectively down-regulate, as well as over-express PDGF-C in this line. Here, PDGFC is linked to central nervous system cancer.