S100A9 and neoplasm: In addition to suppressing immunity, CXCL1 and CXCL2 also recruit myeloid cells to produce paracrine factors such as S100A9 and promote tumor cell survival (Acharyya et al., 2012; Alafate et al., 2020) found that silencing CXCL1 can down-regulate NF-κB and mesenchymal cell transformation, and inhibit the growth of human glioma xenograft (Alafate et al., 2020).