Intriguingly, while CXCL1 induces, by hundreds and thousands of times, tumor-promoting and immunosuppressive factors, it also promotes, though to a lesser extent, the expression of IL15, CXCL9, CXCL10, CXCL11, which can lead to T and NK cell recruitment and anti-tumor responses (Tagaya et al., 1996; Palacios-Arreola et al., 2014), and down-regulates CCL2, CCL28, IDO, PTGS2, TNF and CXCR4, that may inhibit inflammation and cancer cell migration (Müller et al., 2001; Ali and Lazennec, 2007; Howe, 2007). Here, PTGS2 is linked to cancer.