Quantitative real-time reverse transcriptase polymerase chain reaction (RT-PCR) analysis revealed that treatments of the astrocytoma cell line 1321N1 cells with triterpenes (5 μg/mL) for 48 h upregulate ngf and bdnf expression compared with DMSO-treated cells (Figure 2). Here, NGF is linked to astrocytoma (excluding glioblastoma).