CXCL8 and cancer: In analyses of the molecular mechanisms we found that following TNFα stimulation of such co-cultures, p65 was activated in both cell types but more so in the cancer cells; moreover, p65 activation mainly in TNBC cells, but also in the MSCs, up-regulated the expression and activation of Notch1 in the tumor cells, which then promoted CXCL8 production primarily in the cancer cells [98] (Figure 1(C2)).