Here, two main lines of evidence were obtained: the first is that Notch pathway activities have given rise to tumor-promoting functions in BC via IL-6 and STAT3 activation (Figure 1(B1)), and the second is that IL-6 stimulation/STAT3 activation has led through Notch family members to pro-metastatic activities in BC (Figure 1(B2)). This evidence concerns the gene STAT3 and breast cancer.