DLL4 and neoplasm: Our recent bioinformatics study documented that Notch2, Notch3 and DLL4 are potential drivers of Notch signaling in BCa, supporting the view that Notch signaling plays a crucial role in the progression and development of BCa via modulating the cell cycle, regulating the tumor immunity, and direct or indirect interactions with well-known cancer-related pathways such as p53, TSC/mTOR, RAS/MAPK, and PI3K/AKT [24].