S100A9 and neoplasm: The results from the nude mouse xenograft model showed that co-injection with HCT116/Fn-treated Mφ significantly accelerated the tumor growth, and this effect was partially blocked by silencing S100A9 expression in Mφ in the nude mice co-injected with HCT116/(Fn + siS1A00A9)-treated Mφ (Figure 6A).