In this context, IL-8 induction by SMAD4 knock-down results in neutrophil recruitment into the TME via the IL-8 receptor CXCR2 (Figure 1A); these tumor-associated neutrophils (TAN), in turn, overexpress IL-8 when compared to peripheral blood neutrophils [23]. The gene discussed is CXCL8; the disease is neoplasm.