In addition, cells pretreated with Smad1-specific siRNA increased the basal endoenous E-cadherin protein (Fig. 4B) and mRNA (Fig. 4C) expressions in DAPT-untreated cells, and the DAPT treatment also further downregulated E-cadherin expressions in LN18 glioma cells (Fig. 4B and 4C). Here, SMAD1 is linked to central nervous system cancer.