SCUBE3 and central nervous system cancer: Because SCUBE3 expression levels in the test glioma cell lines follows the trend U251 > U87 > U373 (Fig. 4b), and SCUBE3 overexpression rescued the inhibition of U251 induced by CN-3 (Fig. 4e), the U251 cell line was selected to for further experiments to determine the underlying mechanisms of CN-3 treatment.