S100A9 and neoplasm: However, there was no significant effect on cell apoptosis when downregulated S100A9. Regarding the involved pathways, studies have shown that S100A8/A9 induces the activation of the NF-κB pathway, which increases the expression of CXCL1, CCL5, CCL7, and so on, whose products are known in angiogenesis, tumor migration, wound healing, and the formation of pre-metastatic niches into the surrounding tissue and organs [37].