A significantly reduced stimulation was observed by efferocytic peritoneal macrophages, which could be explained by their polarization towards M2, as shown in Figure 2B. Moreover, efferocytosis inhibition of bone marrow-derived macrophages (4°C) resulted in decreased Cxcl5 and unchanged Cxcl1 and IL-6 expression, which confirmed that the pro-inflammatory response of bone marrow-derived macrophages is produced by efferocytosis of apoptotic cancer cells. This evidence concerns the gene CXCL1 and cancer.