JAG1 and neoplasm: To determine whether Notch1 signaling could potentiate NF-κB signaling, we incubated GFP-p65-expressing 231 and 6DT1 tumor cells with vehicle control, TNFα, Jagged1 (Notch1 ligand expressed on macrophages) [36], or both TNFα and Jagged1 combined for four hours and measured the intensity of green fluorescence signal in the nucleus over time.