Role of DLL1 and Notch signaling in cell invasion. (A) Representative pictures showing increase in cell invasion after activation of Notch signaling by transfection of NCID and recombinant DLL1 treatment. The invasion of the cells was reduced by treatment with anti-DLL1 antibody. (B) Quantification of cell invasion relative to the untreated control cells. (n = 4). (C) Cell proliferation expressed as relative to the respective control cells. (n = 4).* p < 0.05.