DLL4 and breast cancer: Fractionated radiation of BC cells has led to increased production of IL-6 and CXCL8, and inhibition of each of these factors has given rise to reduced tumor cell migration and invasion (Figure 1(B2)); here, it was also found that IL-6 acted through JAK/STAT3 to activate Notch2-Jag1/DLL4 interactions that elevated EMT characteristics in BC cells [109] (Figure 1(B2)).